Former FBI Director James Comey will settle several open questions on Thursday about his interactions with President Trump regarding the investigation into potential Russian collusion.

But those answers will open up new lines of inquiry which senators can be expected to raise during Comey’s testimony before the Senate Intelligence Committee on Thursday.

WATCH LIVE:

In his opening statement for Thursday’s session, Comey will tell the Senate panel that he assured Trump on three separate occasions — Jan. 6, Feb. 14, and March 30 — that the Republican was not personally under investigation as part of the Russia collusion investigation. (RELATED: Trump Lawyer Says He Feels ‘Completely And Totally Vindicated’ By Comey Testimony)

That is seen as good news for Trump, who claimed in his May 9 letter firing Comey that the FBI chief had provided those assurances.

On the negative side for the commander in chief, Comey will confirm reports that Trump asked him in the Feb. 14 meeting to end an investigation into former national security adviser Michael Flynn regarding his conversations with Russia’s ambassador. That revelation has already led to obstruction of justice allegations against Trump. (RELATED: Here Are Comey’s Prepared Remarks)

But Comey’s comments, which were previewed in a seven-page document released by the Senate panel, raises a whole new slew of questions about Trump and the Russia investigation.

Why couldn’t Comey say in public what he said in private?

Comey will testify that in addition to telling Trump three times that he was not under investigation, he provided the same information to Congress during closed briefings.

That discrepancy is said to be one of the main sources of Trump’s frustration with Comey. It has also been a concern for one of the lawmakers briefed on the same information given to Trump.

Senate Judiciary Committee chairman Chuck Grassley hinted last month that Comey had told him that Trump was not a target in the investigation.

“I said he should tell the public what he told Senator Feinstein and me about whether the FBI is or is not investigating the President,” Grassley said in a Judiciary Committee meeting.

Comey will suggest in his testimony that he was hesitant to make public assurances about Trump in case the Russia investigation eventually turned up evidence implicating the former real estate mogul. But Comey can expect to be asked to explain his rationale for withholding the information from the public.

Dossier and Jan. 6 briefing

In his statement, Comey appears to cast some doubt on the claims made in a dossier compiled by former British spy Christopher Steele.

The document, which was published by BuzzFeed News on Jan. 10, alleges that Russian operatives have videos of Trump with Russian prostitutes in a Moscow hotel room. The dossier also alleges that Trump campaign officials colluded with Kremlin operatives to influence the election.

Comey offers no support for the dossier in his prepared remarks. He plans to say that he brought up the document in the meeting with Trump because intelligence community leadership thought it was appropriate “to alert the incoming President to the existence of this material, even though it was salacious and unverified.”

Comey will also state that Trump was briefed because the intelligence community officials knew that “the media was about to publicly report the material and we believed the IC should not keep knowledge of the material and its imminent release from the President-Elect.”

He will also state that “to the extent there was some effort to compromise an incoming President, we could blunt any such effort with a defensive briefing.”

Comey could be asked how he knew that the dossier was soon to be published. He could also be asked if he believed that the possible compromise effort against Trump was based in fact or fiction.

The “defensive briefing” cited by Comey may also generate interest from the Senate panel.

Comey would also have a chance to reveal, if he so desires, whether the FBI relied on the dossier as the basis for part of its investigation and whether he had any concerns that Steele, the former spy, was being paid by an opposition research firm connected to supporters of Hillary Clinton.

FBI officials reportedly cited the dossier in an application for a Foreign Intelligence Surveillance Act warrant filed in September against former Trump campaign adviser Carter Page.

Page is mentioned in the dossier as the Trump campaign’s liaison to the Kremlin, allegations which he has strongly denied.

Obstruction of justice?

Some Comey watchers have speculated that he is unlikely to give a definitive answer on whether Trump obstructed justice by requesting an end to the Flynn investigation or asking him to publicly reveal the extent of the Russia probe.

Even if nothing bad comes to Trump & Co. from the Russia investigation itself, Democrats will hammer away on Trump’s requests to Comey. Trump’s persistence that Comey publicly announce that was not the center of the Russia investigation — as well as a request for a loyalty pledge during the Jan. 27 meeting — will only help bolster the Democrats’ case.

But Comey is a former federal prosecutor and deputy attorney general. If asked by the Senate panel to wear those hats, Comey could expect to be asked whether he considered Trump’s requests to constitute obstruction of justice.

What “other concerns” did Trump have about Flynn?

Comey will say that Trump’s request to end the Flynn portion of the FBI’s investigation centered on the retired lieutenant general’s calls with Russia’s ambassador, Sergey Kislyak.

Comey states that he did not interpret Trump’s request to be about the larger Russia investigation. But Comey will also suggest that Flynn had created other problems for the White House.

“He added that he had other concerns about Flynn, which he did not then specify,” Comey will say.

Flynn is at the center of several investigations. He may have lied to the FBI about his calls with Kislyak. He may also have misled the Defense Intelligence Agency about payments he received from RT, the Russia-owned media outlet.

Grand jury subpoenas have also reportedly been issued as part of an investigation into Flynn’s lobbying for the Turkish government while serving as a Trump campaign adviser.

Did Comey believe Trump’s denials?

Comey will say that Trump on several occasions denied any wrongdoing related to Russia, including campaign collusion or any of the steamy allegations laid out in the dossier.

“He said he had nothing to do with Russia, had not been involved with hookers in Russia, and had always assumed he was being recorded when in Russia,” Comey will say, recalling a March 30 phone conversation with Trump.

Comey could be asked whether he believed Trump’s denials, both based on the evidence he had seen in the investigation and on his reading of Trump.

Why did Comey continue meeting with Trump? Why didn’t he resign?

Comey will say that he felt uncomfortable meeting one-on-one with Trump. He will also state that after the Feb. 14 Oval Office encounter, he asked Attorney General Jeff Sessions to never leave him alone with Trump because he felt it was inappropriate.

But Comey portrays himself as a passive participant in the meetings. That raises the question of why, if he felt uncomfortable with the Trump encounters, he didn’t put a stop to them earlier.

Comey notes that he met with or talked to Trump one-on-one a total of nine times during their short working relationship. Comey talked to President Obama only twice in three years, he said.

Follow Chuck on Twitter