FBI Director James Comey testifies during a hearing concerning Russian meddling in the 2016 United States election on March 20. (Photo by Drew Angerer/Getty Images)

FBI Director James Comey testifies during a hearing concerning Russian meddling in the 2016 United States election on March 20. (Photo by Drew Angerer/Getty Images)

The head of the Federal Bureau of Investigation announced publicly for the first time today that the agency is looking into Russian hacking during the 2016 presidential election, and he also refuted claims that former President Barack Obama spied on President Trump before the election.

FBI Director James Comey confirmed that the agency is investigating allegations that Russians meddled in the election to President Donald Trump’s advantage at a hearing held by the House intelligence committee on the matter. The agency is also looking into any potential connections between Trump campaign aides and the Russian government, Comey said. The investigation has been ongoing since July.

President Trump tweeted this morning that the allegation of his campaign’s collusion is “FAKE NEWS and everyone knows it!” He also said that Democrats “made up and pushed the Russian story as an excuse for running a terrible campaign,” and officials should be looking into “the leaking of Classified information.”

But National Security Agency Director Michael Rogers said at the hearing that the intelligence community stands behind its January assessment “that it is highly confident Russia interfered in the 2016 election with the goal of electing Donald Trump.” Rogers said that his agency is working to give Congress the information it needs to investigate the findings.

During the hearing, Comey also told the House panel that the FBI and the Justice Department have no information to support Trump’s claims that former President Barack Obama wiretapped Trump Tower before the election. He said that “no individual can order surveillance of an American,” and it’s something that courts approve “after a rigorous application process.”

Rogers also confirmed that President Obama did not ask the British intelligence community to conduct electronic surveillance on Trump.

President Trump made the wiretapping allegation, without any evidence, two weeks ago on Twitter.

In light of Comey’s testimony, Democratic Senate Minority leader Charles Schumer tweeted that President Trump “needs to retract his claim immediately.” He also said in a statement that Trump “severely damaged his credibility” by tweeting the claim and “attempting to put unproven theories into the fringes of American media into the mainstream.”

New Mexico Senator Martin Heinrich co-signed in a tweet saying that President Trump “needs to come clean & admit that he made-up wiretapping claim.”