Trump demands Congress probe into wiretapping by Obama administration

US President Donald Trump on Sunday demanded that US Congress should investigate the "potentially politically motivated" wiretapping of him ordered by his predecessor Barack Obama during the 2016 presidential race.

The White House said in a statement that reports concerning such politically motivated investigations "are very troubling".

"President Donald J Trump is requesting that as part of their investigation into Russian activity, the congressional intelligence committees exercise their oversight authority to determine whether executive branch investigative powers were abused in 2016," Xinhua news agency quoted the statement as saying.

It added that neither the White House nor the President will comment further until such oversight is conducted.

On Saturday, Trump openly claimed Obama had his "wires tapped" in Trump Tower in New York before the 2016 Election Day in November.

"Terrible! Just found out that Obama had my 'wires tapped' in Trump Tower just before the victory. Nothing found. This is McCarthyism!" Trump tweeted in a series of five tweets on Saturday morning.

Trump also compared the alleged wiretapping by Obama to the "Watergate" scandal, which brought down former Republican President Richard Nixon after it was exposed that he ordered wiretapping of the Democratic Party in the 1970s.

Trump did not disclose how he got the information, nor provide any proof to support his accusation against Obama.

However, Obama immediately refuted Trump's accusation as "simply false", Xinhua news agency added.

"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," Obama's spokesman Kevin Lewis said in a statement on Saturday.

"As part of that practice, neither President Obama nor any White House official ever ordered surveillance on any US citizen. Any suggestion otherwise is simply false," he said.

Trump's "wiretapping" accusation came after days of media reports about the contacts between some members of his campaign team and Russian Ambassador to the US Sergey Kislyak.

US Attorney General Jeff Sessions said on Thursday he will recuse himself from any current or future investigations into Russia's possible link with Trump's presidential campaign, after admitting he met with Kislyak twice last year but didn't reveal it at the Senate hearings for his confirmation.

There have been suggestions that contacts between Trump campaign team and Russia were picked up by intelligence agencies as part of routine surveillance of the Russians.

Trump and his aides have denied there were any improper contacts. But the media reports about the phone talks between Trump's former National Security Advisor Michael Flynn with Kislyak during the transition period already led to Flynn's resignation in February.

Several congressional committees are currently investigating Trump team's contacts with Russia, which was accused of interfering in the 2016 US presidential race to help Trump through hacking activities. Russia has strongly denied such accusation.