U.S. President Donald Trump delivers remarks after visiting the National Museum of African American History and Culture on the National Mall in Washington, U.S., February 21, 2017. REUTERS/Jonathan Ernst -

WASHINGTON (Reuters) - U.S. President Donald Trump criticized the FBI on Friday for failing to stop leaks of national security information to the media and directed the agency to find those who pass on classified information.

Trump's comments come amid media reports saying the FBI refused a White House request to knock down news stories saying members of Trump's team were in frequent contact with Russian intelligence agents during the presidential campaign.

The Federal Bureau of Investigation, the nation's top law enforcement agency, did not answer a request for comment on Trump's remarks on Twitter.

"The FBI is totally unable to stop the national security 'leakers' that have permeated our government for a long time. They can't even find the leakers within the FBI itself. Classified information is being given to media that could have a devastating effect on U.S. FIND NOW," Trump wrote.

News reports by CNN and The Associated Press said White House Chief of Staff Reince Priebus asked Andrew McCabe, the FBI deputy director, to deny a Feb. 14 New York Times report that said Trump's presidential campaign advisers had been in frequent contact with Russian intelligence officers. The request came after McCabe told him privately the report was wrong.

A senior administration official said on Friday that FBI Director James Comey also told Priebus later the story was not accurate. Priebus asked if the FBI could set the record straight, but Comey said the bureau could not comment.

Priebus asked if he could say intelligence officials assured him the story was inaccurate, and Comey said he could, the official told reporters.

The FBI is investigating Russian interference in the Nov. 8 U.S. election. FBI counterintelligence agents are also examining financial transactions by Russian individuals and companies who are believed to have links to Trump associates.

"There are investigations that are going on and those investigations must find out exactly what Russia was doing in the United States," Senator Ben Cardin, the top Democrat on the Senate Foreign Relations Committee, told CNN on Friday.

"We need a complete investigation and we certainly don't want the White House at all trying to influence that investigation."

U.S. Representative John Conyers said any White House attempt to influence the FBI was "deeply troubling."

"The White House is simply not permitted to pressure the FBI to make public statements about a pending investigation of the President and his advisors," Conyers, the top Democrat on the House Judiciary Committee, said in late on Thursday.

(Reporting by Susan Heavey, Doina Chiacu and Emily Stephenson; Editing by Chizu Nomiyama and Bernadette Baum)