U.S. President Donald Trump says he "will be proven right" in his accusation that former President Barack Obama wiretapped his telephones at Trump Tower in New York.
The publisher of the Newsmax Media website, Christopher Ruddy - a friend of Trump's - wrote Sunday the president told him "This will be investigated. It will all come out. I will be proven right."
Ruddy said he has never seen Trump this angry in a long time.
The president accused Obama Saturday of bugging his phones a month before the November vote as part of the Obama administration's probe into alleged Russian meddling in the election.
Trump has not shown any evidence to back up his claim.
Obama's Director of National Intelligence James Clapper calls the charge simply false.
"There was no such wiretap activity mounted against the president-elect at the time, or as a candidate or against his campaign," Clapper told NBC's Meet the Press.
Democrats are dismissing the Trump charges of spying as absurd and desperate.
"The president is in trouble," Democratic leader Chuck Schumer said on Meet the Press. "If he falsely spread this kind of misinformation, that is so wrong. It's beneath the dignity of the presidency. . .it shows this president doesn't know how to conduct himself."
The top Democrat on the Intelligence Committee, Senator Mark Warner, told CBS's Face the Nation he was "surprised" by Trump's accusation. "To make that type of claim without any evidence is, I think, very reckless."
Some Republicans were not as quick to blast the president, but are still skeptical . Senator Marco Rubio said on NBC Trump "will have to answer as to what exactly" he was referring to in making the claim that his phones were tapped.
Republican Senator Tom Cotton of the Intelligence Committee told Fox News the wiretap charges will be a part of the investigation into alleged Russian election interference and Trump campaign contacts with Russian officials.
Under U.S. law, a president cannot order someone's phone to be wiretapped. He would need approval by a federal judge and would also have to show reasonable grounds to suspect why a citizen's telephone calls should be monitored.
U.S. intelligence has concluded Russia hacked into the computer of Clinton campaign chief John Podesta, with the anti-secrecy group WikiLeaks then releasing thousands of his emails in the weeks before the election. It was apparently part of a Russian effort to help Trump beat Democrat Hillary Clinton in the presidential election.