Fired FBI director James Comey recently asked lawmakers to help him secure more "resources" for the bureau's counterintelligence investigation of possible connections between President Trump's campaign team and Russian officials, sources told Fox News Wednesday.

The Justice Department repeatedly denied Wednesday that Comey had asked Deputy Attorney General Rod Rosenstein to bolster the Russia probe.

The sources said Comey met with Sens. Richard Burr, R-N.C., and Mark Warner, D-Va., — the chairman and ranking member, respectively, of the Senate intelligence committee — to discuss the ongoing inquiry Monday, the day before the FBI Director was fired by Trump.

During their meeting, Burr and Warner pressed Comey to speed up the investigation. According to the sources, Comey responded that he needed more manpower and asked the senators to help him get it.

It was not immediately clear whether Comey made a similar request to the Justice Department. Senior DOJ officials told Fox News that Comey and Rosenstein, who is overseeing the Russia investigation, had not met since May 1, and Comey had not requested any more resources during that meeting.

Rosenstein's memo to Attorney General Jeff Sessions recommending Comey's dismissal makes no mention of the investigation, which is also probing Russia's hacking of Democratic groups during last year's election campaign.

In a 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 Rosenstein's scathing review of how Comey handled the investigation into Hillary Clinton's email practices, including his decision to hold a news conference announcing its findings and releasing "derogatory information" about Clinton.

Trump, in his letter, pointedly 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.

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, including Burr, joined them in raising alarms of how it could affect probes into possible coordination between Trump associates and Russia to influence the election.

Fox News' Mike Emanuel and Jake Gibson contributed to this report. The Associated Press also contributed to this report.