President Donald Trump defended on Wednesday his firing of former FBI Director James Comey, asserting in a flurry of tweets that both Democrats and Republicans "will be thanking me." Trump did not mention any effect the dismissal might have on FBI and congressional investigations into contacts between his 2016 election campaign and Russia.

"He wasn't doing a good job. Very simply. He was not doing a good job," Trump said in brief remarks to reporters in the Oval Office, where he was joined by former Secretary of State Henry Kissinger.

Comey's abrupt dismissal threw into question the future of the FBI's investigation into the Trump campaign's possible connections to Russia and immediately raised suspicions of an underhanded effort to stymie a probe that has shadowed the administration from the outset. Trump has ridiculed the investigations as "a hoax" and denied any campaign involvement with the Russians.

Questions swirled Wednesday about who ordered the review of Comey's performance that led to his termination and when the decision was made. Sen. Dianne Feinstein said Trump told her he asked the top officials in the Department of Justice to look into a "mess" at the FBI, but White House deputy press secretary Sarah Huckabee Sanders said Trump made the decision Tuesday after the officials came to him with their recommendation.

Democrats compared Comey's ouster to President Richard Nixon's "Saturday Night Massacre" during the Watergate investigation and renewed calls for the appointment of a special prosecutor. Some Republicans also expressed serious concern.

Ironically, Kissinger, who was meeting with Trump, was Nixon's secretary of state in 1973, just moved over from being Nixon's national security adviser.

A White House official said that Trump met with now-Acting FBI Director Andrew McCabe earlier in the day Wednesday, NBC News reported. The official did not immediately provide more details on the meeting. Sanders said Trump has confidence in McCabe.

Comey had briefed Congress days before he was fired that he had requested more staff and money for the Russia investigation from Deputy Attorney General Rod Rosenstein, sources told NBC News and The Associated Press.

The president was not aware of that request, Sanders said, referring a reporter's question on it to the Justice Department. A representative for the department denied to The New York Times, which first reported on it, that such a request had been made.

Earlier Wednesday, Senate Democratic leader Chuck Schumer of New York urged Attorney General Jeff Sessions and Rosenstein to appear before the Senate to answer questions about the circumstances surrounding Trump's action.

However, Senate Majority Leader Mitch McConnell brushed aside calls for a special prosecutor, saying a new investigation into Russian meddling would only "impede the current work being done." He noted that Democrats had repeatedly criticized Comey in the past and some had called for his removal.

Trump made a similar case on Twitter, saying Comey had "lost the confidence of almost everyone in Washington," adding: "When things calm down, they will be thanking me!"

Vice President Mike Pence said at the Capitol that Trump had made "the right decision at the right time."

The Justice Department said Sessions was interviewing candidates to serve as an interim replacement. McCabe, Comey's deputy and an FBI veteran, became acting director after Comey was fired.

In his brief letter Tuesday to Comey, Trump said the firing was necessary to restore "public trust and confidence" in the FBI. The administration paired the letter with a scathing review by Rosenstein, the recently confirmed deputy attorney general, of how Comey handled the investigation into Democrat Hillary Clinton's email practices, including his decision to hold a news conference announcing its findings and releasing "derogatory information" about Clinton.

"Having a letter like the one that he received and having the conversation that outlined the basic atrocities in circumventing the chain of command in the Department of Justice, any person of legal mind and authority knows what a big deal that is," Huckabee Sanders said.



While Comey has drawn anger from Democrats since he reopened the email investigation in the closing days of last year's campaign, they didn't buy that justification for his firing. Several Republicans joined them in raising alarms of how it could affect probes into possible coordination between Trump associates and Russia to influence the 2016 presidential election.

In one of the strongest statements by Republicans, Sen. Richard Burr of North Carolina, chairman of the Senate intelligence committee, said, "I am troubled by the timing and reasoning of Director Comey's termination."

"His dismissal further confuses an already difficult investigation by the committee," Burr said.

Schumer told Trump in a phone call he thought dumping Comey was a mistake. On Wednesday, Trump labeled the Senate minority leader "Cryin' Chuck Schumer."

Trump will now appoint a successor at the FBI, which has been investigating since late July, and who will almost certainly have an impact on how the investigation moves forward and whether the public will accept its outcome.

It was only the second firing of an FBI director in history. President Bill Clinton dismissed William Sessions amid allegations of ethical lapses in 1993.

Trump's confidence in Comey eroded over time, Huckabee Sanders said, given several missteps over years. But Trump had cheered some of Comey's decisions cited in the letter when they were made, like Comey's decision to discuss Hillary Clinton's private email server without Justice Department approval.

"The president was wearing a different hat at that time. Those circumstances certainly change when you become president," Sanders said, when asked to explain the divergent reactions.

Sanders said the president had considered firing Comey "since the day he was elected president."

She said Wednesday that the president had "lost confidence" in Comey and acted on the advice of the deputy attorney general and others.

The topic of reviewing the leadership at the FBI came up when Rosenstein and Sessions were at the White House on other business, she said. "The topic came up, they asked to speak with the president and that's how it moved forward."

But Feinstein, the California Democrat, told reporters: "When I talked to the President last night he said, 'The department's a mess, I asked Rosenstein and Sessions to look into it, Rosenstein sent me a memo, I accepted the recommendation to fire him.'"

Democrats compared the ouster to Nixon's decision to fire the independent special prosecutor overseeing the Watergate investigation in 1973, which prompted the resignations of the Justice Department's top two officials.

"This is Nixonian," Sen. Bob Casey, D-Pa., declared on Twitter. "Outrageous," said Oregon Sen. Ron Wyden, calling for Comey to immediately be summoned to testify to Congress about the status of the Trump-Russia investigation. Rep. Adam Schiff of California, top Democrat on the House intelligence committee, said the White House was "brazenly interfering" in the probe.

Republican Sen. John McCain of Arizona said Congress must form a special committee to investigate Russia's interference in the election.

McConnell, R-Ky., said: "Once the Senate receives a nomination, we look forward to a full, fair and timely confirmation process to fill the director position. This is a critical role that is especially important as America faces serious threats at home and abroad."

Trump, in his letter to Comey, thanked Comey for telling him three times "that I am not under investigation." The FBI has not confirmed that Comey ever made those assurances to the president. In public hearings, Comey has declined to answer when asked if Trump is under investigation, urging lawmakers not to read anything into that statement.

NBC's Asher Klein and AP writers Darlene Superville, Ken Thomas, Vivian Salama, Catherine Lucey, Sadie Gurman and Michael Balsamo contributed to this report.