"I'm very anxious that our president is suggesting that the former president has done something illegal", he said.
Press Secretary Sean Spicer tweeted his statement Sunday morning, calling "reports" of wiretapping "troubling".
The president sparked a firestorm on Saturday by leveling a stunning and unsubstantiated accusation against his predecessor, suggesting Obama ordered surveillance on his residence at New York's Trump Tower.
Here is what the spokesperson for Obama had to say: "A cardinal rule of the Obama Administration was that no White House official ever interfered with any independent investigation led by the Department of Justice".
Clapper said that as far as he knows there was no Foreign Intelligence Surveillance Court Act (FISA) order to monitor Trump Tower.
James Clapper, who served as Director of National Intelligence under Obama, on Sunday flatly denied that there was a wiretap authorized against Trump or his campaign during his tenure in the White House. Those wiretapped communication then were reportedly provide to the White House.
"If this happened", Sanders said, "this is the biggest overreach and the biggest scandal". "Let's get the truth here".
Pelosi termed Trump's contentions about Obama and an attempt at deflection. It would have been taken to a judge by investigators, but investigators never did that, the former official said.
Senate Democratic leader Chuck Schumer of NY said Trump had either made a false accusation, or a judge had found probable cause to authorize a wiretap.
On his show Thursday, conservative radio host Mark Levin said Mr. Obama was "using powers of the federal government to surveil members of the Trump campaign".
Trump officials have demanded an investigation into claims Obama had telephones at Trump Tower wiretapped.
"JUST IN: White House statement: Congressional investigation will include "whether executive branch investigative powers were abused in 2016", CBS tweeted on Sunday".
The allegations came as calls mounted for Attorney General Jeff Sessions to resign for not admitting during his confirmation hearing he had contacts with Russian Ambassador Sergey Kislyak during the campaign.
Flynn had told Vice President Mike Pence he had not discussed USA sanctions with the Russians, but transcripts of intercepted communications showed that the subject had come up in conversation.
A spokesman for Obama denied that the former president, or any other White House official, had ordered surveillance on a private US citizen. Former president Obama imposed sanctions on Russia and expelled Russian diplomats.in December over the country's involvement in hacking political groups in the presidential election.