WASHINGTON — House Intelligence Committee Chairman Devin Nunes denied on Monday morning that there was any evidence from the intelligence community of contacts between Trump campaign officials and Russian operatives.

"As of right now, I don't have any evidence of any phone calls. It doesn't mean they don't exist. . . . What I've been told by many folks is that there's nothing there," Nunes, R-Calif., said.

Nunes contended there was no need at this time for a special prosecutor to investigate allegations of contact between Russian officials and Trump campaign aides. Instead, the Republican said that the "major crimes" that have been committed are leaking to the news media on the subject of Russia, as well as other accounts of what should be confidential dealings with the Trump White House, including calls with foreign leaders like the Australian prime minister.

"There's been major crimes committed," Nunes said, referring to the leaks. "What I'm concerned about is no one is focusing on major leaks that have occurred here. . . . We can't run a government like this. A government can't function with massive leaks at the highest level."

This is the first time a leading House Republican - in this case, the lawmaker who is leading the investigation in the lower chamber - has said flatly that he has not seen any evidence of inappropriate communications between Trump aides and Russia. The FBI is investigating Russia's role in last year's elections, and potential ties between Trump associates and Russia.

Nunes also rejected the call by Democrats that he would request Trump's tax returns, which they believe would shine light on possible Trump business dealings with Russia.

Democrats pushed back forcefully on the idea that conclusions could be drawn even before the investigation has really gotten up and running.In a Monday afternoon news conference, top Intelligence Committee Democrat Adam Schiff, Calif., argued Nunes's conclusions are "premature."

Schiff pointed to the fact that the committee has not yet received any documents, called any witnesses, or even released the final agreement about the scope of its investigation. Schiff said he expect that framework to be announced later on Monday.

"When you begin an investigation, you don't begin by stating what you believe to be the conclusion," Schiff told reporters.

The dueling press conferences are the latest sign that House Republicans and Democrats are divided about how to probe allegations that members of Trump's team had improper contacts with Russian officials. Schiff has agreed to make the leaks part of the House Intelligence panel's investigation - but he warns that the focus should be on the substance of what was leaked, particularly as it pertains former national security adviser Michael Flynn's contact with Russian officials.

Over Nunes's objections, Schiff is angling for the committee to receive transcripts of Flynn's conversations with Russian ambassador Sergey Kislyak.

"Whether it was leaked or not leaked doesn't inhibit us from doing the necessary investigation," Schiff said. He said he has "yet to be convinced" the FBI would be fully cooperative with the congressional investigation.

Both the House and Senate Intelligence committees are probing what intelligence officials say is Russia interference in last year's elections aimed at helping to elect Trump. Nunes signaled that his committee would be operating by its own rules instead of working in close tandem with the Senate, which has pledged a bipartisan investigation of Russian involvement in the elections.

In a morning news conference, Nunes rejected the idea that former senator Jeff Sessions, R-Ala. - a close Trump adviser during the campaign who is now attorney general - should recuse himself from any Justice Department probe on the topic.

The GOP chairman confirmed that he was one of the lawmakers to whom the White House turned to combat a New York Times story saying there were frequent contacts between the Trump campaign and Russian officials. That report mentioned Flynn, former Trump campaign manager Paul Manafort and former campaign aide Carter Page, as well as Trump associate Roger Stone.

"At this time, I want to be very careful that we can't just go on a witch hunt against Americans because they appear in news stories," Nunes said.

He described the White House passing on to him a phone number for a reporter. The California Republican said he didn't see anything inappropriate with the request and his behavior.

"I had already talked to many of you about that several times," Nunes said, explaining he was only passing on "whatever I had already told you." "Isn't the whole point of the press to be transparent?"

But Schiff said the White House "seeking help from intelligence leadership ... to knock down stories it doesn't like is completely inappropriate."

The chairman's comments come after a Washington Post story describing the Trump administration's efforts to enlist the intelligence community to knock down media stories about Trump associates' ties to Russia.

Nunes said that the committee was still determining the scope of its investigation into alleged Russian participation in the U.S. elections to tilt the outcome toward Trump, a conclusion drawn by the intelligence community.

But he seemed reluctant to blame Flynn for inappropriately discussing sanctions before Trump's inauguration with Sergey Kislyak, the Russian ambassador to the United States, according to current and former intelligence officials.

Flynn was asked to leave the White House after it was revealed he misled Vice President Mike Pence about discussing sanctions against Russia with Kislyak.

Nunes said we should be thanking Flynn for his service to the country and that the retired lieutenant general was only trying to prepare a new president for office. He said he has not seen the transcripts of Flynn's call with the Russian ambassador, which would have been "illegally leaked" if he had.

He described Flynn as having done a "big favor" by "keeping lines of communication" open with Russia after President Barack Obama expelled Russian officials from the United States in response to allegations that country interfered in the U.S. elections.

Nunes said we should "be thanking" Flynn and "not going after him."

Nunes also took issue with the definition of sanctions - which were imposed on Russia in 2014 for the annexation of Crimea and Russia's involvement in Ukraine - saying that in his view, Flynn was not discussing official sanctions in his conversations with Kislyak but rather the "petty" retaliation against such officials by Obama.

He called "ridiculous" any suggestion that Flynn could be charged under the Logan Act - a 1799 statute that has never been used to prosecute U.S. citizens for interfering in foreign policy.