US President Donald Trump walks from Marine One as he returns to the White House in Washington, US, March 5, 2017.[Photo/Agencies]

PALM BEACH, Florida — President Donald Trump turned to Congress on Sunday for help finding evidence to support his unsubstantiated claim that former President Barack Obama had Trump's telephones tapped during the election. Obama's intelligence chief said no such action was ever carried out, and a US official said the FBI has asked the Justice Department to dispute the allegation.

Republican leaders of Congress appeared willing to honor the president's request, but the move has potential risks for the president, particularly if the House and Senate intelligence committees unearth damaging information about Trump, his aides or his associates.

Trump claimed in a series of tweets without evidence Saturday that his predecessor had tried to undermine him by tapping the telephones at Trump Tower, the New York skyscraper where Trump based his campaign and transition operations, and maintains a home.

Obama's director of national intelligence, James Clapper, said nothing matching Trump's claims had taken place.

"Absolutely, I can deny it," said Clapper, who left government when Trump took office in January. Other representatives for the former president also denied Trump's allegation.

The FBI has asked the Justice Department to dispute Trump's allegations, a US official told The Associated Press on Sunday. The official wasn't authorized to discuss the request by name and spoke on condition of anonymity.

No such statement has been issued by the Justice Department. DOJ spokeswoman Sarah Isgur Flores declined to comment Sunday, and an FBI spokesman also did not comment.

The New York Times reported that senior American officials say FBI Director James Comey has argued that the claim must be corrected by the Justice Department because it falsely insinuates that the FBI broke the law.

White House press secretary Sean Spicer said without elaborating Sunday that Trump's instruction to Congress was based on "very troubling" reports "concerning potentially politically motivated investigations immediately ahead of the 2016 election." Spicer did not respond to inquiries about the reports he cited in announcing the request.

Spicer said the White House wants the congressional committees to "exercise their oversight authority to determine whether executive branch investigative powers were abused in 2016." He said there would be no further comment until the investigations are completed, a statement that House Democratic leader Nancy Pelosi took offense to and likened to autocratic behavior.

"It's called a wrap-up smear. You make up something. Then you have the press write about it. And then you say, everybody is writing about this charge. It's a tool of an authoritarian," Pelosi said.