Trump impeachment hearings Day 3: Vindman testifies about why the Ukraine call alarmed him Here is how the the hearing unfolded throughout the day.

Day 3 of the House impeachment hearings wrapped on Tuesday evening after the committee questioned four witnesses over the course of more than nine hours.

Tuesday's hearings ended with two witnesses requested by Republicans: Kurt Volker, the former U.S. special envoy to Ukraine, and Tim Morrison, a National Security Council official who was on President Donald Trump's July 25 call with Ukraine's president. The two were questioned for about five hours.

Republicans wanted Morrison, a political appointee, to repeat what he said in his closed-door deposition: that he heard nothing illegal on the call, although he was concerned that, if it leaked, there could be political fallout.

Volker, one of the so-called "three amigos" communicated with William Taylor, the top U.S. diplomat in Ukraine, and Gordon Sondland, the U.S. ambassador to the European Union, about what Trump wanted from Ukraine, but reportedly will claim he was out of the loop when it came to specific demands about investigations.

Earlier Tuesday, two White House national security aides on the July phone call who expressed concerns about the statements Trump made to Ukraine's leader became the first current White House officials to testify publicly in the Democrats' impeachment investigation.

Army Lt. Col. Alexander Vindman, the National Security Council's Ukraine expert, testified alongside Jennifer Williams, a national security aide to Vice President Mike Pence. They were questioned for about 4.5 hours.

Here is how the the hearing unfolded throughout the day.

8:29 p.m.

Schiff adjourned Tuesday's hearing after making an impassioned plea for Americans to take an interest in the president's conduct and calling impeachment "a powerful anti-corruption measure."

"The idea of withholding that military aid to get these political investigations should be anathema and repugnant to every American, because it means the sacrifice not just of Ukrainian national security, but American national security for the interests of the president personally and politically," Schiff said.

"My Republican colleagues all they seem to be upset with this -- not that the president sought an investigation of his political rival, not that he withheld a White House meeting and $400 million in aid -- their objection is he got caught. Their objection is someone blew the whistle and they would like this whistle blower identified, and the president wants this whistle-blower punished. That's their objection. Not the president engaged in this conduct, but that he got caught. Their defense is, well he ended up releasing the aid. Yes, after he got caught. That doesn't make this any less odious," he added.

8:06 p.m.

A Democratic congressman spoke about the "weighty" decision to advocate for impeaching the president, a decision he said members would "have to grapple with."

Rep. Denny Heck, D-Wash., laid out the implications of impeachment in broader terms – and the difficulties that lie ahead.

"Look, none of us wants to be here, despite what's being said. None of us came to this easily. I didn't. I will recall for the rest of my life the 48 hours I spent at our family cabin literally plunged in self-reflection and literally prayerful deliberation about this whole matter," Heck said. "Collectively we're going to have to grapple with this very grave decision."

"It's weighty, and it's going to get hard," Heck continued. "And it's hard in proportion to its importance to our great republic. A republic if we can keep it," he said, paraphrasing a quote attributed to Benjamin Franklin.

7:45 p.m.

The former U.S. special envoy to Ukraine said the U.S. is "not pushing back hard enough on Russia, and that we owe Ukraine a great deal of support."

Volker’s impassioned declaration came towards the closing of Tuesday night’s public testimony before the House Intelligence Committee. He testified that "Russia is trying to upend security in Europe," making clear the reason why withholding aid to Ukraine is against American interests.

"If we want to live in a world of freedom for the United States, we ought to be supporting freedom for people around the world," Volker concluded.

7:25 p.m.

Despite the president’s overtures to Ukraine’s leader for an investigation into the Bidens, Morrison said he never pressed his counterparts in Kiev to implement the president’s wishes.

"You just testified that the president sets the foreign policy objectives for the United States," Rep. Eric Swalwell, D-Calif., said.

"And the one call you listened to between the president of the United States and the president of Ukraine, the president of the United States priorities were to investigate the Bidens. And I'm asking you, sir, why didn't you follow up on the president's priorities when you talked to the Ukrainians?"

"Sir, I did not understand it as a policy objective," Morrison said.

7:20 p.m.

The Ukrainians chided Volker when he encouraged them not to investigate one of President Zelenskiy’s former political rivals.

Recounting a conversation he had with Andriy Yermak, an aide to Zelenskiy, Volker said when he "cautioned [Yermak] to say that pursuing prosecution … risks deepening the divisions in the country."

In response, "Mr. Yermak said, well, what, you mean, like, asking us to investigate Clinton and Biden?" Volker said.

6:48 p.m.

Volker had previously called the president’s July 25 phone call with Ukraine’s leader "unacceptable."

On Tuesday, under questioning by Rep. Jim Himes, D-Conn., Volker said "it is the reference to Vice President Biden" that he found unacceptable.

In the July 25 phone call, the president repeatedly invoked Biden’s name, and asked Zelenskiy to "look into it … it sounds horrible to me."

6:26 p.m.

Ahead of Ambassador Gordon Sondland’s testimony on Wednesday, Morrison described a turn of phrase used by his predecessor on the NSC, Fiona Hill, to describe Sondland’s role in executing the alleged quid pro quo: "The Gordon problem."

"Among the discussions with Dr. Hill were about Ambassador Sondland – I think she might have coined it ‘the Gordon problem,’" Morrison said.

"I decided to keep track of what Ambassador Sondland was doing … he wanted to get a meeting [between Zelenskiy and Trump]. I understood what the president wanted to do – and had agreed to – a meeting. I was tracking we needed to schedule a meeting."

Morrison was describing his use of the word "tracking" in an email to Sondland in July 2019, which he said Tuesday referred to his tracking of the efforts to coordinate a meeting between Trump and Zelenskiy.

Schiff pushed Volker on the account of the July 10 meeting he initially provided lawmakers.

"We were asking you specifically about what you knew about these investigations. You didn't remember that Gordon Sondland had brought us up in the July 10th meeting with Ukrainians and ambassador Bolton called an end to the meeting. Ambassador Bollton described that meeting as a some drug deal that Sondland and Mulvaney cooked up. You have no recollection of that?" Schiff asked.

"I did not remember that at the time of my October 3rd testimony," Volker answered. "I read the account by Alex [Vindman] and that jogged my memory. I said yes, that's right. That did happen. I do not, still to this point, remember it being an abrupt end to the meeting," Volker said. "The meeting was essentially over. And we got up, we went out to the little circle in front of the white house. We took a photograph. It did not strike me as abrupt."

"I learned over things, including seeing statements from Alex Vindman and Fiona Hill, and that reminded me that yes, at the very end of that meeting, as was recounted in Colonel Vindman's statement, I did remember that, yes, that's right, Gordon did bring that up, and that was it."

Other elements of Vindman’s testimony did not reflect Volker’s memory of events.

"I do not still to this point being an abrupt end to the meeting," Volker said, despite what others have testified.

5:45 p.m.

Schiff orders a short break.

Just before, Morrison, who oversaw Lt. Col. Alexander Vindman’s work on the National Security Council, said he wished Vindman had come to him with concerns about the July 25 call before alerting in-house legal counsel.

"If he had concerns about something, about the content of the call, that's something I would have expected to have been notified of," Morrison said.

Morrison, who also approached lawyers about the call, added that "since we both went to the lawyers … an economy of effort may have prevailed" had Vindman brought the matter before Morrison.

During his testimony this morning, Vindman said he went straight to the NSC legal staff after listening to the president’s phone call with Ukraine’s leader. Vindman said he "attempted to report [his concern] to Mr. Morrison," but that Morrison "didn't avail himself."

5:08 p.m.

Morrison recounted his concern with Ambassador Sondland’s conduct with regard to "requirements" the Ukrainians needed to meet in order to receive the U.S. security aid.

In relaying what he said Sondland told him about his conversations with the Ukrainians, Morrison said Sondland told him "that the Ukrainians would have to have the prosecutor general make a statement with respect to the investigations as a condition of having the aid lifted."

"I was concerned about what Ambassador Sondland was saying were requirements," Morrison added. "I was concerned about what I saw essentially as an additional hurdle."

At the outset of Republicans’ questioning period, Nunes said he had "bad news" for the two witnesses.

"TV ratings are way down, way down," Nunes said. "Don't hold it personally. I don't think it's you guys. Whatever ‘drug deal’ the Democrats are cooking up here, the American people aren't buying it."

Nunes’ reference to a "drug deal" referred to testimony from former NSC aide Fiona Hill, who said that former national security adviser John Bolton instructed her to inform NSC lawyers that he would not take "part of whatever drug deal Sondland and Mulvaney are cooking up," referring to the alleged quid pro quo arrangement and acting White House chief of staff Mick Mulvaney.

4:49 p.m.

Morrison testified that he approached NSC legal counsel John Eisenberg and Eisenberg’s deputy, Michael Ellis, to review the transcript of Trump's July 25 phone call and to limit who would have access to it.

He testified that he was concerned about "potential political fallout" if the call's contents were leaked.

Morrison also said he later learned that the transcript had been moved into a highly classified, separate server, but upon asking Eisenberg why, Morrison said he was told that was a "mistake."

4:45 p.m.

Kurt Volker testified that he did not think Ukraine’s cooperation in launching investigations was a "necessary condition" to earning a White House meeting, but that it would have been "very helpful."

"I wouldn't have called it a condition. It's a nuance, I guess," Volker said. "But I viewed it as very helpful. If we could get this done, it would improve the perception that President Trump and others had and we would get a date for a meeting."

4:32 p.m.

Morrison described his disappointment after listening in live to President Trump’s July 25 phone call with Zelenskiy, noting that he "was hoping for a more full-throated statement of support from the president concerning president Zelenskiy’s reform agenda."

He added he advocated for records of the call to be placed in a "highly classified system" for fear of leaks and the subsequent "political consequences."

Asked whether he found it improper that the president advocated for an investigation into the Bidens, Morrison said, "It’s not what we recommended the president discuss."

4:12 p.m.

As Schiff began his questions, Volker reiterates his past testimony that he does not suspect Democrat Joe Biden did anything wrong.

"It is not credible to me that former Vice President Biden would have been influenced in any way by financial or personal motives in carrying out his duties as Vice President," Volker says.

Volker says he also didn't believe accusations against Marie Yovanovitch, the former U.S. ambassador to Ukraine. He says those were not credible either.

"I have known former Vice President Biden for a long time. I know how he respects his duties of higher office, and it's just not credible to me that a vice president of the United States is going to do anything other than act as how he sees best for the national interest," Volker says.

3:27 p.m.

The afternoon session begins with statements from Chairman Adam Schiff and Ranking Member Devin Nunes.

"Welcome back to Act Two of the circus, ladies and gentlemen," Nunes said at the beginning of his opening statement.

Nunes and his Republican colleagues have staunchly defended the president’s conduct towards Ukraine and sought to cast the impeachment inquiry as a partisan attack.

The two witnesses were then sworn in and made their opening statements.

In opening remarks, Kurt Volker made note of "a great deal of additional information" he has learned since his Oct. 3 closed-door deposition in front of impeachment investigators, including details of the alleged quid pro quo effort conducted by President Trump.

"At the time I was connecting [Ukrainian chief of staff Andriy] Yermak and Mr. Giuliani, and discussing with Mr. Yermak and Amb. Sondland a possible statement that could be made by the Ukrainian President, I did not know of any linkage between the hold on security assistance and Ukraine pursuing investigations," Volker said.

He insisted he never "knowingly took part in an effort to urge Ukraine to investigate former Vice President Biden."

Volker said he was not aware of many key revelations that have come to light since his first appearance before the committee in October, including Ambassador Gordon Sondland’s phone call with President Trump during which the president allegedly said his priority in Ukraine was "the investigations."

He also said he has never used the term "The Three Amigos," which other witnesses in the impeachment probe have used to describe Volker, Ambassador Sondland, and Energy Secretary Rick Perry.

Volker said he does not think the Ukrainians were aware of a hold on military aid until Aug. 29, a day after Politico reported that the money had been frozen.

Other witnesses testified in separate closed-door hearings that their Ukrainian counterparts had figured it out earlier than that. The State Department's Catherine Croft couldn't give an exact date the Ukrainians found out, other than it was "earlier than I expected them to."

Bill Taylor, the U.S. diplomat in Ukraine, testified last week in open testimony that he thinks "there’s still some question as to when they may have heard."

When exactly Ukraine knew the money was on hold is a key point for Republicans, who contend that Trump can't be accused of personally imposing a "quid pro quo" in his July 25 phone call because, they say, Ukraine had no idea that military aid was on hold at that time.

1:40 p.m.

As the first part of Tuesday's hearing ended, Schiff thanked Williams and Vindman for their testimony.

"We have courageous people like yourself who come forward, who report things, who do what they should do, who have a sense, as you put it, colonel, of duty, of duty. Not to the person of the president, but to the presidency and to the country. And we thank you for that," Schiff said.

He added that even though other witnesses have testified about remarks the president didn't care about Ukraine outside the investigations of the Bidens, members of Congress still care about the longstanding U.S. policy in Ukraine.

"The president may not care about it, but we do. We care about our defense, we care about the defense of our allies. And we darned well care about our constitution," Schiff said.

In his closing remarks, Republican Rep. Rep. Devin Nunes says "Act One of today's circus is over ... the Democrats are no closer to impeachment than where they were three years ago."

The second hearing was expected to begin in about an hour.

1:25 p.m.

Democrat Rep. Sean Maloney asked Vindman what went through his mind when he heard Trump on the July 25 call.

"Frankly, I couldn't believe what I was hearing. It was probably an element of shock that maybe in certain regards, my worst fear of how our Ukraine policy could play out was playing out, how this was likely to have significant implications for U.S. National security," Vindman said.

"And you went immediately and reported it, didn't you?" Maloney asked.

"I did," VIndman answered

"Why?" Maloney then asked.

"Because that was my duty," Vindman responded.

Maloney then asked Vindman to again read the passage of his opening statement that mentioned his father.

After Maloney asked why he told his dad not to worry about his safety for testifying, Vindman said, "Congressman, because this is America. This is the country I have served and defended, that all of my brothers have served and here, right matters."

A number of people in the audience then began applauding.

1:21 p.m.

Democratic Rep. Sean Maloney lamented the political attacks against Vindman in the hearing during his time for questioning.

"We've even had a member of this committee question -- this is my favorite -- question why you would wear your dress uniform today. Even though that dress uniform includes a breast plate that has a combat infantry badge on it and a purple heart medal ribbon," he said.

"It seems like if anybody gets to wear the uniform, it's somebody who's got a breastplate with commendations on it."

Republican Rep. Chris Stewart noted that Vindman was wearing his dress uniform "knowing that's not the uniform of the day" earlier in the hearing, even though active duty military officers are required to be in uniform when appearing in an official capacity.

Vindman told Stewart he felt the attacks against him have "marginalized" him as a military officer. A spokesperson for the Army told ABC News they are supporting Vindman with concerns around his family's security as he testifies in the impeachment inquiry.

12:59 p.m.

Referring to a theory put forth by Rudy Giuliani, the president's personal lawyer, and President Trump that it was Ukraine, not Russia, that interfered in the 2016 presidential election, Vindman called it a "Russian narrative that President Putin has promoted."

"And are you aware of any part of the U.S. Government, its foreign policy or intelligence apparatus that supports that theory?" Rep. Castro, D-Texas, asked Vindman.

"No, I'm not aware," Vindman said.

The theory that Ukraine framed Russia in election interference in 2016 has been widely criticized. Tom Bossert, Trump's former Homeland Security Adviser and now an ABC News Contributor, took aim at Giuliani in September on ABC's "This Week," telling ABC News Chief Anchor George Stephanopoulos that the theory is "completely false."

12:55 p.m.

Under questioning from Democratic Rep Jackie Speier, Vindman suggests he may have already experienced retaliation from the White House.

"In both your situations since you have given depositions and have you seen your experience in your respective jobs change or have you been treated any differently?" Speier asked. Williams said she had not but Vindman said he was excluded from meetings since he raised concerns about the July 25 call.

"I did notice I was being excluded from several meetings which would have been appropriate for my position," Vindman said.

"So, in some respects there have been reprisals?" Speier said.

"I'm not sure I could make that judgment. I would say it's out of the course of normal affairs to not have me participate in some of these events," Vindman said.

12:47 p.m.

Down Pennsylvania Avenue from the hearing at the Capitol, President Trump, speaking to reporters at the White House, struck a dismissive tone when asked whether he thinks Lt. Col. Vindman is a credible witness, making note of the moment when Vindman corrected Nunes for referring to him as "Mr. Vidman" and also seemed to question his motives in wearing a military uniform to testify.

"I don't know him, as he says Lieutenant Colonel, I understand someone had the misfortune of calling him 'mister' and he corrected them. I never saw the man, I understand now he wears his uniform when he goes in. No, I don't know Vindman at all," Trump said during a Cabinet meeting, ABC's Jordyn Phelps reports.

A U.S. official told ABC News' Elizabeth McLaughlin at the Pentagon that Vindman testifying before Congress means he is serving in his official capacity and therefore is required to wear the uniform.

Separately, an Army spokesperson told ABC's Luis Martinez: "A soldier performing duties in an official capacity will normally be in uniform. In cases where a soldier is detailed to an agency outside of DoD, the individual would follow the policies of that agency."

12:43 p.m.

Asked whether Hunter Biden’s role on the board of Burisma may have presented the appearance of a conflict of interest, both Vindman and Williams responded in the affirmative.

"Certainly the potential, yes," Vindman said.

"Yes," Williams chimed in.

Republicans have called on Hunter Biden to testify as part of the impeachment inquiry, but Democrats have thus far declined to call him before the committee.

12:17 p.m.

Republican Rep. John Ratcliffe started his question time by referring to House Speaker Nancy Pelosi’s Thursday news conference at which she said the president was engaged in "bribery."

Ratcliffe, piling copies of all the deposition transcripts on the desk in front of him, claimed that not once have any witnesses used that word to describe what the president did, even if they were concerned.

Chairman Schiff then came back to this argument and defended using the term.

"I want to make one thing clear for folks watching today. Bribery does involve a quid pro quo. Bribery involves the conditioning of a specific act for something of value," Schiff said.

He added "The reason we don't ask witnesses, who are fact witnesses, to make a judgment about whether a crime or bribery has been committed. …. For one thing, you may not be aware of all the facts brought forward in this investigation."

11:54 a.m.

Democrat Rep. Jim Himes also insinuated that Republicans were accusing Vindman of disloyalty to the U.S. in his line of questioning about when Vindman was offered the position of defense minister for Ukraine, which Vindman said he denied.

"That may have come cloaked in a Brooks Brothers suit and in parliamentary language, but that was designed exclusively to give the right wing media an opening to questioning your loyalties," Himes said.

"And I want people to understand what that was all about. It's the kind of attack -- it's the kind of thing you say when you're defending the indefensible," Himes said.

"Colonel Vindman, would you call yourself a 'Never Trumper?'" Himes asked at one point.

"Representative, I'd call myself 'Never Partisan'" Vindman replied.

Moments earlier, Himes suggested the president engaged in "witness intimidation" in calling Jennifer Williams a "Never Trumper" on Twitter.

"Ms. Williams, are you engaged in a presidential attack?" Himes, D-Conn., asked.

"No, sir," she replied emphatically.

Williams went on to say that the president’s tweet "certainly surprised" her and that she did not consider herself a "Never Trumper."

"It surprised me, too," Himes said. "It looked like witness intimidation and tampering in an effort to perhaps shape your testimony today."

11:50 a.m.

In the first extended effort to undercut Vindman’s credibility, Rep. Jim Jordan, R-Ohio, read testimony from another former National Security Council official, Tim Morrison, who said he heard concerns that Vindman may have leaked classified information to the press.

"That is preposterous that I would do that," Vindman shot back. "I can’t say why Mr. Morrison questioned my judgment."

Vindman read from a performance review prepared by his former boss at the NSC, Fiona Hill, who gave him glowing feedback on his work.

11:35 a.m.

Chairman Schiff gavels the hearing back in.

Vindman said there was no "ambiguity" in President Trump’s invoking the name "Biden" during his July 25 call with Ukraine’s president.

"It was pretty clear that the president wanted Zelenskiy to commit to investigate the Bidens?" Schiff asked.

"That’s correct," Vindman said.

"One of the ‘favors’ that you properly characterized as a demand," Schiff added.

"That's correct," Vindman responded.

11:18 a.m.

Schiff asks Vindman if he would like to take a short break and Vindman says he would.

11:14 a.m.

Republican Counsel Steve Castor asked Vindman if he was offered the position of Ukrainian defense minister during the trip to Ukrainian President Zelenskiy’s inauguration.

Vindman said he was offered the position three times but dismissed it each time and reported it to his commanding officer.

"I'm an American. I came here when I was a toddler and I immediately dismissed these offers. Did not entertain them," he said.

"The whole notion was rather comical," Vindman added, saying he didn’t "leave the door open at all" to the offer.

11:07 a.m.

ABC's Ben Siegel notes this exchange between Castor and Vindman:

Vindman said he recalled Sondland discussing "Burisma, the Bidens and the 2016 elections" in the July 10 meeting at the White House with Ukrainian officials.

GOP counsel Steve Castor followed up, claiming that Vindman, behind closed doors, didn't initially recall whether the election came up. Vindman said that he clarified that later in his testimony.

"So when we asked the question, it sort of refreshed your recollection?" Castor said.

"Yes, I guess that's a term now," Vindman replied with a smile.

Sondland, in his updated testimony, said he had "refreshed his recollection."

10:50 a.m.

During a testy exchange about the whistleblower whose complaint brought to light the nature of the July 25 phone call, Vindman corrected Nunes when the Republican ranking member referred to him as, "Mr. Vindman."

"Ranking member, it's Lieutenant Colonel Vindman, please," Vindman said.

In a lengthy series of questions about the whistleblower – and whether Vindman knew the person’s identity – Nunes grew frustrated when Vindman appeared to avoid answering directly.

"You can answer the question, or you can plead the Fifth," Rep. Nunes said, referring to Vindman’s Fifth Amendment right not to incriminate himself.

Chairman Schiff interjected, telling Nunes the hearing would not be used as a vehicle for Republicans to unmask the whistleblower.

Vindman's lawyer Michael Volkov also defended his client, saying it was not a matter of possibly pleading the Fifth. ABC's Trish Turner in the hearing room reports this is the first time we have heard extensive remarks from a lawyer at these hearings.

10:39 a.m.

Vindman pushed back on Nunes’ line of questioning about whether he discussed President Trump’s phone call with Ukrainian President Zelenskiy on July 25 with reporters.

"I do not engage with the press at all," Vindman said.

Republican allies of the president have accused Vindman and other "bureaucrats" in the administration of politically motivated leaking.

It's clear the GOP suspects that Vindman tipped off the whistleblower, although Vindman says he's not sure who the whistleblower is.

Vindman does acknowledge that he shared the contents of the July 25 phone call with a member of the intelligence community as well as State Department official George Kent.

10:26 a.m.

Vindman says he told U.S. Ambassador to the European Union Gordon Sondland that discussion of investigations of the Bidens and the 2016 election were inappropriate when he says Sondland brought them up after a meeting with American and Ukrainian officials.

"I said that this request to conduct these meetings was inappropriate. These investigations was inappropriate and had nothing to do with national security policy," Vindman said.

10:19 a.m.

Vindman says he had already been tracking the "alternative narrative" around Ukraine when he decided to immediately report the July 25 call to NSC lawyers.

"At this point, I had already been tracking this initially what I would describe as alternative narrative, false narrative, and I was certainly aware of the fact that it was starting to reverberate, gain traction," he said.

He also said there was a discussion among NSC lawyers about how to handle the transcript and keep it to a "smaller group" to avoid the sensitive information from being leaked, but that he didn't see it as "nefarious."

10:13 a.m.

ABC News' Mary Bruce notes that Vindman is contradicting the White House readout of the April 21 call between Presidents Trump and Zelenskiy.

"Vindman says his talking points encouraged the president to raise the issue of corruption. At the time, the White House readout of the call said the issue came up. But Vindman notes the president never actually raised the issue. And the transcript that the White House released last week shows it was not brought up," Bruce says.

Vindman testified that he was on that call and that corruption was part of the National Security Council recommended talking points for the president, but that he does not recall the issue of corruption coming up on the call.

ABC's Ben Siegel reports from the hearing room that Vindman also said, as he did in private testimony, that he warned Zelenskiy against involvement in U.S. domestic politics.

10:03 a.m.

In describing President Trump’s asking Ukraine’s leader to launch investigations that may help his 2020 reelection effort, Vindman relayed his experience in the military to describe why he understood Trump’s overture as "an order," not a "request."

"Chairman, the culture I come from – the military culture – when a senior asks you to do something, even if it's polite and pleasant, it’s not to be taken as a request. It's to be taken as an order," Vindman said.

"In this case, the power disparity between the two leaders, my impression is that in order to get the White House meeting, President Zelenskiy would have to deliver these investigations."

ABC News Political Director Rick Klein tweets this analysis: "A key point that the witnesses last week made too - that a "favor" is more like a demand in light of Ukraine's reliance on the US"

10:01 a.m.

Both Vindman and Williams say they remember hearing the word "Burisma" on the July 25 phone call, but that it was omitted in the transcript. "It's not a significant omission," Vindman said, but said he tried to correct the record. Burisma is not mentioned in the transcript released by the White House.

Burisma is the gas company in Ukraine that hired Hunter Biden to sit on its board.

9:47 a.m.

Vindman, delivering his opening statement in his U.S. Army uniform, pushes back on criticisms brought forth by the president’s allies, insisting his role in the impeachment inquiry comes not from bipartisan bias, but "under a common oath to protect and defend the Constitution of the United States of America."

"We do not serve any particular political party, we serve the nation. I am humbled to come before you today as one of many who serve in the most distinguished and able military in the world," Vindman says.

On Monday, Sen. Ron Johnson, R-Wis., suggested Vindman was a "bureaucrat" who "never accepted President Trump as legitimate and resent his unorthodox style," and indirectly accused him of "leaking to the press and participating in the ongoing effort to sabotage his policies."

Vindman notes his brother is in the audience and then directs his testimony at his father, who fled the Soviet Union 40 years ago and brought Vindman and his brother to the United States.

Vindman said he and his sibling chose public service to repay the country that took them in. Vindman also notes that his actions, if in Russia, would have "surely cost me my life." Then he assured his father "do not worry, I will be fine for telling the truth."

9:38 a.m.

Williams gives her opening statement first, defending her service in the U.S. diplomatic corps after President Trump targeted her on Twitter over the weekend.

"As a career officer, I am committed to serving the American people and advancing American interests abroad, in support of the President’s foreign policy objectives," Williams said Tuesday.

"I found the July 25th phone call unusual, because in contrast to other presidential calls I had observed, it involved discussion of what appeared to be a domestic political matter."

9:22 a.m.

Ranking Member Devin Nunes blamed media coverage of the hearings last week for overstating the impact of last week’s testimony and continued calls for more information about the whistleblower whose complaint launched the impeachment inquiry.

Schiff has said he does not know the identity of the whistleblower and will protect them from being publicly identified due, in part, to security concerns.

9:17 a.m.

The president has called both witnesses "Never Trumpers."

Schiff notes the attacks on Williams and Vindman.

"Ms. Williams, we all saw the President’s tweet about you on Sunday afternoon and the insults he hurled at Ambassador Yovanovich last Friday. You are here today, and the American people are grateful," Schiff says. "Col. Vindman, we have seen far more scurrilous attacks on your character, and watched as certain personalities on Fox have questioned your loyalty. I note that you have shed blood for America, and we owe you an immense debt of gratitude."

9:09 a.m.

House Intelligence Committee Chairman Adam Schiff opens the hearing by reviewing what other witnesses have testified, saying President Donald Trump has "placed his own personal and political interests above those of the nation."

Vindman and Williams are sitting side-by-side at the witness table as Schiff introduces them as having been alarmed by the July 25 call.

9:01 a.m.

ABC News Senior Congressional Correspondent Mary Bruce notes that today's witnesses provide some of the testimony that prompted the impeachment inquiry by raising concerns about the administration's dealings in Ukraine.

"Today we are going to be hearing from witnesses who were on that phone call that sparked this entire impeachment inquiry and they have described what they heard as unusual and inappropriate," Bruce says.

8:45 a.m.

Jennifer Williams has arrived as well. She will be today's first witness. The hearing room is filling up quickly with congressional staff, reporters and spectators.

Tuesday's hearing starts off an important week in the impeachment inquiry after the first two days of public testimony last week.

If you missed last week's hearings you can catch up on some of the key takeaways from former U.S. ambassador to Ukraine Marie Yovanovitch and the first hearing with William Taylor, the top U.S. diplomat in Ukraine, and George Kent, the State Department's top career official tasked with Ukraine policy.

8:15 a.m.

Army Lt. Col. Alexander Vindman has arrived in Capitol Hill in his dress blue uniform. He was accompanied by his brother, Yevgeny, who also serves on the National Security Council as an ethics lawyer.

Vindman told investigators, according to a transcript of his closed session, that he was "concerned" by the call, adding that he "did not think it was proper to demand that a foreign government investigate a U.S. citizen," a reference to the suggestion from Trump that Ukraine investigate former Vice President Joe Biden's son, Hunter Biden, and his work for Ukrainian energy company Burisma. He also told lawmakers there was "no doubt" in his mind about what Trump sought from Ukraine in the July phone call with Zelenskiy.

In his private testimony, Vindman also told lawmakers he repeatedly raised his concerns about the president's comments -- along with the discussion of the investigations that Rudy Giuliani, Trump's personal lawyer, was publicly calling for -- with NSC lawyers.

He also said he attempted to get nearly $400 million in military aid to Ukraine restored after it was put on hold over the summer, drafting a memo that the president refused to sign.

The Iraq War veteran, who received a Purple Heart, is expected to appear in uniform.

Williams said in a separate closed session with lawmakers that she found the mention of investigations into the 2016 election and unsubstantiated theories of Ukraine's meddling in the race, and a probe into the Biden family's dealings in Ukraine "unusual and inappropriate."

The president has lashed out at both officials, calling Vindman a "never Trumper" as he testified to Congress last month, and criticizing Williams after her closed-door testimony was released over the weekend.

Tim Morrison, a departing NSC official who was also on the Trump-Zelenskiy call, will testify Tuesday afternoon. While he raised concerns about the call to White House lawyers -- specifically, how a leak of the transcript would be received in a polarized Washington, and impact bipartisan support for Ukraine -- he previously told impeachment investigators that he was "not concerned that anything illegal was discussed," according to a transcript of his deposition released by House Democrats.

Lawmakers will also question former U.S. envoy to Ukraine Kurt Volker on Tuesday afternoon.

Republicans, who requested the public testimony from both officials, believe elements of their accounts undermine Democrats' concerns about the withholding of aid for investigations at the center of the impeachment inquiry.

Tuesday's testimony could set the stage for the upcoming appearance of Gordon Sondland, Trump's ambassador to the European Union and an apparent central player in the efforts to encourage Ukraine to launch investigations that could benefit Trump politically.

The House Intelligence Committee is scheduled to hold a total of five public hearings this week with nine witnesses.

Sondland will testify Wednesday morning, followed by senior Defense Department and State Department officials Laura Cooper and David Hale.

Fiona Hill, the NSC's former Russia expert under former national security adviser John Bolton, is scheduled to appear on Capitol Hill Thursday morning, along with Holmes.