Comey had pushed for more resources for Russia probe before being fired by Trump: source

• In shock move, Trump fires FBI Director Comey
• Clinton blames FBI's Comey for her defeat in call with donors
• Ex-Obama administration officials to testify in Trump-Russia probe

With the Republican president facing a storm of criticism from many Democratic lawmakers and some in his own party, the Trump administration accused Comey of "atrocities" on the job and denied his firing was related to the FBI's Russia investigation.

Trump, who met Russia's foreign minister at the White House on Wednesday, lashed out at critics, calling Democrats "phony hypocrites," and defended his decision to abruptly oust Comey on Tuesday from the law enforcement post he held since 2013.

FILE PHOTO: A combination photo shows U.S. President Donald Trump (L) in the House of Representatives in Washington, U.S., on February 28, 2017 and FBI Director James Comey in Washington U.S. on July 7, 2016. REUTERS/Jim Lo Scalzo/Pool, Gary Cameron/File Photo

In a farewell letter to staff seen by CNN, Comey, who was appointed by Trump's predecessor, Democratic President Barack Obama, said he had "long believed that a president can fire an FBI director for any reason, or for no reason at all."

Comey added he would not spend time dwelling on Trump's decision "or the way it was executed."

But Democrats ramped up accusations that Comey's removal was intended to undermine the Federal Bureau of Investigation probe and demanded an independent investigation into the alleged Russian meddling, with some calling the firing an attempt to cover up wrongdoing related to Russia.

A congressional source with knowledge of the matter said Comey told lawmakers within the past few days he had asked the Justice Department to make additional resources available - mainly more staffing - for the Russia probe.

Comey informed lawmakers of that request after the Senate Intelligence Committee, conducting its own investigation, had asked the FBI to speed up its Russia inquiry, the source said.

Democrat Dianne Feinstein, the Senate Judiciary Committee's top Democrat, told reporters she understood Comey was seeking more resources for the FBI investigation.

Responding to media reports that Comey had asked Deputy Attorney General Rod Rosenstein last week for a significant boost in resources for the agency's probe, Justice Department spokesman Ian Prior said in an email: "Totally false."

U.S. intelligence agencies concluded in a January report that Russian President Vladimir Putin had ordered an effort to disrupt the 2016 election that included hacking into Democratic Party emails and leaking them, with the aim of helping Trump.

Russia has denied any such meddling. The Trump administration denies allegations of collusion with Russia.