Two White House national security officials testified before the House's impeachment inquiry on Tuesday that President Donald Trump's request to Ukraine's president to investigate Democratic rivals was inappropriate, and one of them said it validated his 'worst fear' that American policy toward that country would veer off course

Washington: Two White House national security officials testified before the House's impeachment inquiry on Tuesday that President Donald Trump's request to Ukraine's president to investigate Democratic rivals was inappropriate, and one of them said it validated his "worst fear" that American policy toward that country would veer off course.

Hours later, two more witnesses — another former White House national security official and a former top American diplomat — charted a more careful course but said under oath that the president's requests on a 25 July phone call with President Volodymyr Zelenskiy of Ukraine were not in line with US national security goals.

The new accounts came as the House Intelligence Committee opened a packed week of testimony, with nine witnesses scheduled to answer questions before the public before the House decamps for Thanksgiving.

Democrats used Tuesday's back-to-back hearings to move the focus of their growing case into the White House and back to the July phone call they see as the centerpiece of an abuse of power by Trump in which he used his office to try to obtain a political advantage from a foreign power.

Taking their cues from the White House, Republicans moved aggressively to try to undercut the day’s lead witness, Lieutenant-Colonel Alexander S Vindman, the National Security Council's Ukraine expert. They tried to raise questions about Vindman's loyalty to the United States, and sought to portray the concerns expressed by Vindman and an aide to Vice-President Mike Pence as merely the opinions of unelected, and even unreliable, bureaucrats second-guessing the President of the United States.

Vindman responded by invoking his sense of duty as an American and an officer to explain why he was so alarmed by Trump's request that he reported his concerns to White House lawyers.

"I couldn’t believe what I was hearing," Vindman, an Iraq War combat veteran who testified dressed in his deep-blue army dress uniform covered with military ribbons. "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, and how this was likely to have significant implications for US national security."

Sitting beside him during the morning's hearing, Jennifer Williams, a diplomat serving on Pence's national security staff, reiterated that she found Trump's phone call with Zelenskiy "unusual and inappropriate". She said she was struck that Trump was pressing a foreign leader about a personal domestic political issue, though she did not report any concerns at the time and spoke in more reserved terms.

On the call, Trump veered off talking points prepared by Vindman and pressed Zelenskiy to investigate former vice-president Joe Biden and his son Hunter, and a debunked theory that Democrats conspired with Ukraine to interfere in the 2016 election.

Both witnesses testified that as the summer went on, concerns within the American and Ukrainian governments grew over Trump's decision to withhold vital military assistance for the country — a step he took as he pressed for the investigations. National security officials in the United States unanimously supported releasing the aid, they testified, and some raised legal concerns before it was released in September.

Williams recounted a September meeting between Pence and Zelenskiy in which the Ukrainian president explained in dramatic terms how failing to provide the money would only help Russia.

"Any signal or sign that US support was wavering would be construed by Russia as potentially an opportunity for them to strengthen their own hand in Ukraine," Williams said, relaying what Zelenskiy told Pence.

For Vindman in particular, the testimony amounted to an unusual act of public criticism of the president by a White House employee — and it came at an immediate cost.

The colonel, who came to the United States as a refugee at three, referred to his family's history in Ukraine, a former Soviet republic, noting that in Russia, "offering public testimony involving the president would surely cost me my life".

Addressing his father, who he credited with "the right decision" in leaving the Soviet Union to seek refuge in the United States 40 years ago, Vindman said, "Do not worry, I will be fine for telling the truth."

But as Vindman sat in the stately House Ways and Means Committee Room, the official, taxpayer-funded Twitter account of the White House posted a critical quote in which Tim Morrison, his former boss at the National Security Council, questioned Vindman's "judgment".

Morrison, the council's former senior director for Russia and Europe, testified in a second session that went well into Tuesday evening alongside Kurt D Volker, the former US special envoy to Ukraine. Public testimony from both men had been requested by Republicans, but they also confirmed key details of the case Democrats are building against Trump.

In carefully calibrated testimony, Morrison confirmed that he and other White House officials had continuing concerns about Vindman's judgment, though he declined to discuss them at length. Morrison, who listened in on the July 25 call himself from the White House Situation Room, said he wished Vindman had come to him directly with his concerns.

"I think we both agreed we wanted that more full-throated support of Zelenskiy and his reform agenda, and we didn’t get it," Morrison said of the call. He reported it to White House lawyers himself, but only out of concerns it would be politically damaging if leaked.

He said in questioning that he did not view the call as illegal or improper, but added of the requests for investigations that "it’s not what we recommend that the president discuss".

Volker was more withering.

"I don't think that raising 2016 elections or Biden or these things I consider to be conspiracy theories that have been circulated by the Ukrainians" were "things that we should be pursuing as part of our national security strategy with Ukraine," he testified. "We should be supporting Ukraine's democracy, reforms, its own fight against corruption domestically and the struggle against Russia and defence capabilities."

Volker called Biden "an honourable man".

Volker was a key player in negotiations during the summer between the Ukrainian government and the Trump administration over whether Zelenskiy would be granted an Oval Office meeting with the president. Among the conditions put on Zelenskiy was that he make a public commitment to investigating the debunked theory that someone in Ukraine rather than Russia was responsible for a hack of the Democratic National Committee in 2016 and Hunter's role as a board member of a Ukrainian energy company, Burisma.

Much of his testimony revolved around Rudy Giuliani, Trump's personal lawyer, who appears to have instigated a push for investigations, and Gordon Sondland, the ambassador to the European Union who put it into action. Sondland will testify publicly on Wednesday.

Volker testified that while he was aware Trump wanted an investigation of Burisma, he did not make the connection at the time between Burisma and the Bidens.

Volker said that looking back, he misunderstood that other officials meant the Bidens when they mentioned investigations of Burisma.

"In retrospect, I should have seen that connection differently, and had I done so, I would have raised my own objection," he said.

Volker said he was also unaware that other officials saw a connection between the withholding of nearly $400 million in US military aid to Ukraine and Zelenskiy's willingness to commit to the investigations sought by Trump.

"I did not know of any linkage between the hold on security assistance and Ukraine pursuing investigations," he testified. "No one had ever said that to me — and I never conveyed such a linkage to the Ukrainians."

Representative Jim Jordan of Ohio, a top Republican ally of the president's, cited Morrison’s comment about Vindman and criticism from Fiona Hill, his former boss at the National Security Council to ask why the witness' concerns ought to be considered relevant.

"Any idea why they have those impressions?" Jordan inquired. Vindman, who apparently came prepared for the criticism, pulled out a copy of the performance evaluation Hill wrote about him in July, read aloud from it and pressed ahead with his account of what transpired.

Soft-spoken at first, Vindman grew more confident in addressing lawmakers who criticised him as the hearing went on.

"Ranking member, it's Lieutenant Colonel Vindman, please," he instructed the committee's top Republican, Representative Devin Nunes of California, at one point after Nunes addressed him as "Mr Vindman".

In another exchange that touched on Vindman’s loyalty to the United States, Steve Castor, the top Republican staff lawyer, asked him about three instances when Oleksandr Danylyuk, the director of Ukraine's national security council, had approached him with offers to become the country's defence minister.

Vindman confirmed the offers and testified that he repeatedly declined, dismissing the idea out of hand and reporting the approaches to his superiors and to counterintelligence officials.

"Every single time, I dismissed it," he said, adding: "I'm an American. I came here when I was a toddler."

Danylyuk himself said Tuesday that the offer was not a serious one.

Democrats fumed, accusing Republicans of sliming a patriot because he had a politically inconvenient story to tell.

"They’ve accused you of espionage and dual loyalties," said Representative Jim Himes, D-Conn. "The three minutes we asked about the offer making you minister of defence — that may have been cloaked in a Brooks Brothers suit, but that was designed exclusively to give the right-wing media an opening to questioning your loyalties."

Democrats also continued to push back against what they saw as efforts by Republicans to tease out the name of or information about the whistleblower whose account of the 25 July call helped lead to the impeachment inquiry.

Democrats sought throughout both hearings to redirect attention back to actions by Trump, who they believe withheld the $391 million in assistance earmarked for Ukraine and a coveted White House meeting to get the political advantages he thought Ukraine could deliver him.

It may be too early to fully know the effect the hearings are having on public opinion. Television ratings and opinion polls released in recent days suggest that public engagement has so far fallen short not only of hearings at the height of Watergate and the impeachment of former president Bill Clinton, but of earlier blockbuster Trump-era congressional hearings. But it is harder to measure the reach of proceedings online and on social media.

And after three long days of public testimony, House Republicans appear to be holding together in Trump's corner, either unconvinced his behaviour was as the witnesses described or unconvinced that it warrants a remedy as drastic as impeachment.

"An impeachment inquiry is supposed to be clear," said Representative John Ratcliffe, R-Texas. "It's supposed to be obvious, it's supposed to be overwhelming and compelling, and if two people on the call disagree honestly about whether or not there was a demand and whether or not anything should be reported on a call, that is not a clear and compelling basis to undo 63 million votes and remove a president from office."

Nicholas Fandos and Michael D Shear c.2019 The New York Times