Top Republican's cryptic warning of US 'national security threat'

House Intelligence Committee chairman Mike Turner provided no details about the 'serious' national security threat

A top Republican has issued a cryptic warning of a "serious national security threat" facing the US.

Officials in the US have told the BBC's partner there, CBS News, that Russia is developing a nuclear-capable weapon that could take down satellites, thereby knocking out communications.

They said there is no evidence a weapon has actually been deployed.

The White House has said the threat is not imminent, but that congressional leaders would be briefed this week.

Lawmakers have until Friday to review intelligence about it.

Russia has not commented on the reports.

In a statement issued by the chairman of the House Intelligence Committee - the body which oversees the US intelligence community - Mike Turner said only that the committee has "made available to all members of Congress information concerning a serious national security threat".

"I am requesting that President 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," the statement added.

Like many governments around the world, the US classifies sensitive information which it believes could damage national security.

The intelligence is available for lawmakers to view in a secure facility within the US Capitol complex until Friday, 16 February.

Declassifying the information surrounding the threat would mean that US politicians would be able to openly discuss it and the steps they believe they should take.

The top Democrat on the committee, Connecticut's Jim Himes, said in a statement that while the classified threat is "significant", it "is not a cause for panic".

"As to whether more can be declassified about the issues, that is a worthwhile discussion but it is not a discussion to be had in public," he added.

Similarly, House Speaker Mike Johnson said that there is "no need for public alarm".

Senate Intelligence Chairman Mark Warner and Vice-Chairman Marco Rubio said in a statement that their committee had been "rigorously tracking this issue from the start" and "are discussing an appropriate response with the administration".

"We must be cautious about potentially disclosing sources and methods that may be key to preserving a range of options for US action," the statement added.

Asked about the threat at the White House, National Security Advisor Jake Sullivan told reporters that he had offered to personally brief the so-called "Gang of Eight" comprised of House and Senate leaders from both parties and the top lawmakers on the House and Senate Intelligence Committees.

A briefing for the House members of the wider group - which includes Mr Turner, Mr Johnson and Minority Leader Hakeem Jeffries - had been scheduled for Thursday.

"I'm a bit surprised that Congressman Turner came out publicly today in advance of a meeting on the books for me to go sit with him alongside our intelligence and defence professionals tomorrow," Mr Sullivan said. "I'm not in a position to say anything further today."

Mr Sullivan later added that the Biden administration was "protecting the national security of the United States and the American people".

"Americans understand that there are a range of threats and challenges in the world that we're dealing with every single day, and those threats and challenges range from terrorism to state actors," he said. "And we have to contend with them."