The United States is facing a new and “serious” national security threat, top officials warned on Wednesday, with multiple media outlets reporting that it concerned Russia’s military capability.

In a cryptic statement that prompted fellow congressional leaders to reassure the public that there was no cause for panic, US House Intelligence Committee chairman Michael Turner urged lawmakers to review the details.

Unidentified sources told NBC and CNN the threat is a “highly concerning” Russian military capability, while ABC reported that the intelligence was about Moscow wanting to put a nuclear weapon in space, possibly to use against satellites.

“I am requesting that President [Joe] Biden declassify all information relating to this threat so that Congress, the administration and our allies can openly discuss the actions necessary to respond to this threat,” he said, calling it a “serious national security threat”.

Turner and his Democratic counterpart Jim Himes said in a letter to lawmakers the panel had “identified an urgent matter with regard to a destabilising foreign military capability that should be known by all congressional policymakers”.

They said the committee had voted on Tuesday to make classified information available in a secure location for review by lawmakers until Friday.

Himes urged caution however in a separate statement in which he described the intelligence as “significant” but not “a cause for panic”.

The Republican House speaker, Mike Johnson, also urged caution, telling reporters at the Capitol that “there is no need for public alarm”.

“We are going to work together to address this matter, as we do all sensitive matters that are classified,” he said.

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White House National Security Adviser Jake Sullivan signalled frustration that Turner had gone public ahead of a Thursday briefing he is scheduled to deliver to the four House members in the “Gang of Eight” group of party leaders and top intelligence committee members.

“That’s his choice to do that. All I can tell you is that I’m focused on going to see him, sit with him, as well as the other members of the ‘Gang of Eight’ tomorrow,” he said.

The drama played out with Biden and the Republican-led House at an impasse over a White House request for US$60 billion in military aid to help Ukraine’s defence against the Russian invasion entering its third year.

Johnson – who has repeatedly warned he will not address allies’ security until America’s immigration system is shored up – is refusing to bring the Senate-passed bill to the floor for a vote.

“The most urgent national security threat facing the American people right now is the possibility that Congress abandons Ukraine and allows Vladimir Putin’s Russia to win,” said Democratic Minority Leader Hakeem Jeffries.