A spokesman for the Republican-controlled House Intelligence Committee has asked the Justice Department to provide any evidence of the president's wiretapping claims before a March 20 hearing, and warned it could use a "compulsory process" if it doesn't get answers.
House Intelligence Committee Republicans spokesman Jack Langer made the statement Monday after the Justice Department asked for more time "to determine what if any responsive documents may exist."
House Intelligence Committee chairman Devin Nunes, R-Calif., and the committee's ranking Democrat, Adam Schiff, D-Calif., in a letter last week asked the Justice Department to turn over by Monday any evidence showing Trump Tower was wiretapped during the 2016 presidential race. A hearing is scheduled for March 20.
"If the committee does not receive a response by then, the Committee will ask for this information during the March 20 hearing and may resort to a compulsory process if our questions continue to go unanswered," Langer said in a statement.
President Donald Trump made the explosive claim that "Obama had my "wires tapped" in Trump Tower just before the victory" via Twitter on March 4.
Kevin Lewis, a spokesman for Obama, has said "neither President Obama nor any White House official ever ordered surveillance on any U.S. citizen. Any suggestion otherwise is simply false."
Obama's director of national intelligence, James Clapper, on NBC's "Meet the Press" Sunday said that under the part of the national security apparatus that he oversaw "there was no such wiretap activity mounted against the president, the president-elect at the time, or as a candidate, or against his campaign."
More from NBC News
Trump's Backing a Healthcare Plan That Breaks His Promises
American Citizens: U.S. Border Agents Can Search Your Cellphone
White House: CBO 'Simply Has It Wrong' On GOP Healthcare Bill
Earlier Monday, Republican Sen. Lindsey Graham said he hadn't heard back from the FBI about Trump's allegations. Graham and his Judiciary Committee colleague, Sheldon Whitehouse, D-Rhode Island, in a letter last week asked the FBI for information.
"I'm getting very ill-tempered over this," Graham said.
Graham said he planned to give FBI Director James Comey more time, though he urged him to get in touch before talking to the intelligence committee.
"If I were the FBI Director, who I like, I would respond to my letter ... before I publicly testify because you'll run afoul of the Judiciary Committee."
Earlier Monday, White House Press Secretary Sean Spicer told reporters that the president "used the word wiretap in quotes, to mean broadly, surveillance, and other activities."
"He doesn't really think that president went up and tapped his phones personally," Spicer said.
On NBC's "TODAY," White House counselor Kellyanne Conway declined to comment on the issue, citing the House Intelligence Committee investigation, though in an appearance on ABC's "Good Morning America" she had "no evidence" to prove the claim.
In an interview on Sunday, Sen. John McCain, R-Arizona, the chairman of the Armed Services Committee, implored Trump to show his cards.
"The president has one of two choices — either retract or provide the information that the American people deserve," McCain said in an interview on CNN's "State of the Union." "I have no reason to believe that the charge is true, but I also believe that the president of the United States could clear this up in a minute."