Christopher Wray, the white-collar attorney from a prominent Atlanta-based international law firm who is President Donald Trump's pick to lead the FBI, testified at his Senate confirmation hearing that he doesn't believe the ongoing investigation into possible coordination between Russia and the Trump campaign is a "witch hunt."

Wray made this assessment after revelations this week that the president's son, Donald Trump, Jr. had met last year with a Russian lawyer whom he believed would give him damaging information about Hillary Clinton.

The 50-year-old Wray, who served as a high-ranking official in the Justice Department during the George W. Bush administration, asserted his independence during the highly-charged hearing, saying he would never let politics get in the way of the FBI's mission. He told the Senate Judiciary Committee members that he had "way too much respect and affection for the FBI."

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Wray made it clear that he differed with President Trump on several issues, including the Russia investigation, and Mr. Trump's characterization of his fired predecessor, James Comey, as a "nut job."

The soft-spoken Wray appeared calm, confident and cautious as he fielded questions for more than four hours in a Senate hearing room packed with spectators, reporters and family members -- including Wray's wife, their two grown children and his parents.

Under intense grilling by the Senate Judiciary committee, Wray said he met with President Trump and others at the White House twice during the nominating process and was never asked to pledge loyalty to the president.

"[M]y loyalty is to the Constitution, to the rule of law and to the mission of the FBI," he said in reply to a question from Vermont Sen. Patrick Leahy, a Democrat.

No one, he said, asked him for a loyalty oath, "and I sure as heck didn't offer one."

Wray recalled that he went to both meetings with the president and listened very carefully to make sure that he didn't hear anything that would make him uncomfortable.

"And I can assure you, if anything had been said that made me remotely uncomfortable, I would not be sitting here today providing testimony in support of my nomination," he declared.

Leahy asked what Wray would do if Mr. Trump had asked him to do anything illegal or unethical.

"First I would try to talk him out of it, and if I failed, I would resign," he said.

The president fired former FBI Director Jim Comey last May. Comey testified in June that Mr. Trump had asked him for a loyalty pledge and made a request which Comey said he interpreted as wanting him to drop the investigation into former National Security advisor Michael Flynn. He said he refused to comply. Trump has denied making these statements.

Wray is considered to be highly intelligent, has a no-nonsense demeanor and is known to shun the spotlight. He repeatedly voiced his support for Robert Mueller, the special counsel leading the Russia probe and for Comey, who he said he'd found to be a "terrific lawyer, a dedicated public servant and a wonderful colleague."

Wray worked at the Justice Department at the same time as Comey during the Bush administration.

However, he did not agree with Comey's decision to hold a news conference last July about the investigation into Hillary Clinton's email server

"I can't imagine a situation where as FBI director I would be giving a press conference on an uncharged individual," he said, alluding to the fact that Comey announced that he would not recommend that the Justice Department charge Clinton over her handling of classified information.

Wray said, "If I am given the honor of leading this agency I will never allow the FBI's work to be driven by anything other than the facts, the law, and the impartial pursuit of justice. Period. Full stop."

Mr. Wray's nomination is expected to pass with bipartisan support.