WASHINGTON — President Donald Trump on Monday accused Democrats of making up allegations about his campaign associates’ contact with Russia during the presidential election, and said Congress and the FBI should be going after media leaks and maybe even Hillary Clinton instead.

His tweets came just hours before a potentially politically damaging hearing in which FBI Director James Comey and National Security Agency Director Michael Rogers planned to testify on allegations of Russian hacking and whether there were any connections between Moscow and Trump’s campaign.

“The Democrats made up and pushed the Russian story as an excuse for running a terrible campaign. Big advantage in Electoral College & lost!” Trump tweeted early Monday, as news coverage on the Russia allegations dominated the morning’s cable news.

“The real story that Congress, the FBI and others should be looking into is the leaking of Classified information. Must find leaker now!”

He also suggested, without evidence, that Clinton’s campaign was in contact with Russia and had possibly thwarted a federal investigation. U.S. intelligence officials have not publicly raised the possibility of contacts between the Clintons and Moscow. Officials investigating the matter have said they believe Moscow had hacked into Democrats’ computers in a bid to help Trump’s election bid.

“What about all of the contact with the Clinton campaign and the Russians?” he tweeted. “Also, is it true that the DNC would not let the FBI in to look?”

Monday’s hearing before the House Intelligence Committee, one of several congressional panels probing allegations of Russian meddling, could allow for the greatest public accounting to date of investigations that have shadowed the Trump administration in its first two months.

U.S. intelligence agencies concluded that Russia meddled in the campaign to help Trump defeat Democrat Hillary Clinton. The FBI has also been investigating ties between Russia and Trump advisers and associates during the campaign.

The top two lawmakers on the House intelligence committee said Sunday that documents the Justice Department and FBI delivered late last week offered no evidence that the Obama administration had wiretapped Trump Tower, the president’s New York City headquarters. But the panel’s ranking Democrat says the material offers circumstantial evidence that American citizens colluded with Russians in Moscow’s efforts to interfere in the presidential election.

“There was circumstantial evidence of collusion; there is direct evidence, I think, of deception,” Rep. Adam Schiff, D-Calif., said on NBC’s “Meet the Press.” ‘‘There’s certainly enough for us to conduct an investigation.”

Rep. Devin Nunes, the California Republican who chairs the committee, said: “For the first time the American people, and all the political parties now, are paying attention to the threat that Russia poses.”