On Thursday, spokesman Sean Spicer defended the president's comments by repeating a Fox News analyst's report that GCHQ, the British electronic intelligence agency, had helped Obama wiretap Trump.
"Three intelligence sources have informed Fox News that President Obama went outside the chain of command - he didn't use [U.S. intelligence agencies]".
Trump said he "very seldom" regrets anything he tweets, brushing off questions about his claims without evidence that his predecessor, Democrat Barack Obama, wiretapped him during last year's presidential campaign.
It will certainly be interesting to see if Spicer denies the reports that he apologized.
Later, during a joint news conference, Mr Trump pushed back against the notion in Europe that his "America First" agenda means he's an isolationist, calling such a suggestion "another example of, as you say, fake news".
Speaking at a press conference in Washington, Mr Trump said the White House had quoted a legal commentator who appeared on US TV channel Fox News. "He didn't use the NSA, he didn't use the Central Intelligence Agency, he didn't use the Federal Bureau of Investigation and he didn't use the Department of Justice".
Napolitano initially cited "intelligence community members" who believed British intelligence spied on Trump.
Following their day of meetings, the two held a joint news conference Friday afternoon during which Trump stressed the need to protect the US from what he calls "radical Islamic terrorism".
Nunes said on "Fox News Sunday" that leaks to reporters about former Trump national security adviser Michael Flynn were criminal and that his panel was probing whether other names were leaked.
"Well, I've been reading about things", Trump told Carlson.
The government of the United Kingdom received an assurance from the White House that it won't make any more from-the-hip allegations that the Brits spied on then-candidate and now-President Donald Trump, according to the BBC.
It's a freaky, unprecedented spat between the U.S. and one of its closest allies, whose intelligence services work extremely closely together as members of the "Five Eyes" group of countries.
Political reporters and analysts were aghast that the White House would not only stand by the wiretapping conspiracy theory, but also drag Germany into a freakish spat with the United States's closest ally just to dodge responsibility for its own baseless claims.
Republicans in Congress also said Trump should retract his claims.