US intelligence officials have told Congress that Russia is a “full-scope actor” that poses a “major threat” to the United States, as President-elect Donald Trump continues to cast doubt on their conclusion that the Kremlin hacked the Democratic Party to try to influence the presidential election.

Top officials appeared on Capitol Hill on Thursday morning before the Senate Armed Services Committee hearing on “Foreign Cyber Threats to the United States”, chaired by Sen John McCain.

Mr Trump has been critical of the intelligence community’s assessment since it became public in December. In fact, he aligned himself with Wikileaks founder Julian Assange, who published the contents of the Democratic National Committee hack, followed by emails from Clinton campaign chair John Podesta in the final months of the election.

“Russia is a full-scope cyber actor that poses a major threat to US government, military, diplomatic, commercial, and critical infrastructure,” US intelligence chiefs said in a joint statement.

Director of National Intelligence James Clapper expanded on the scope of the “multifaceted campaign” against the US by Russia. He later added that there were “multiple motives” for the cyber-attack.

“The hacking was only one part of it,” he said. “It also entailed classical propaganda, disinformation and fake news.”

Loading....

Mr Clapper added: “We have no way of gauging the impact ... it had on the choices the American electorate made. Whether or not that constitutes an act of war is a very heavy policy call that I don’t believe the intelligence community should make.”

Officials are expected to release a declassified report of their findings to the public on Monday. Mr Obama ordered the full report last month for delivery before he leaves office on 20 January.

The hearing comes a week after President Barack Obama announced sanctions on two Russian intelligence agencies and expelled 35 Russian diplomats.

Trump's advisor suggests Obama's sanctions against Russia are to 'box in' the incoming President

According to Mr Clapper, the sanctions were a “consensus inter-agency view”.

The hearing marks an ongoing rift between Mr Trump and intelligence officials, whom he has attempted to discredit via Twitter since the December assessment alleging Russia’s involvement in the election hacks. He watered down some of his criticism of the agencies on Thursday morning, however, asserting that he is a “big fan” of “intelligence”.

James Clapper listens to questions on Capitol Hill, while testifying before the Senate Armed Services Committee hearing (AP)

Mr Assange has accused the Obama administration of attempting to “delegitimise” Mr Trump ahead of the inauguration.

“They are trying to say that President-elect Trump is not a legitimate President,” Mr Assange told Fox News on Tuesday.

During the interview, he denied Russia’s involvement in their obtaining the hacked documents.