The US has new intelligence on Russian military capabilities related to its efforts to deploy a nuclear anti-satellite system in space, according to multiple sources familiar with the intelligence.The intelligence was briefed to Congress and key US allies, and some lawmakers say it is serious enough that it should be declassified and made public. While the intelligence is concerning, multiple senior members of Congress briefed on the information on Wednesday emphasized that it does not pose an immediate threat to the US or its interests.The system remains under development and is not yet in orbit, according to three US officials familiar with the intelligence. It’s not clear how far the technology has progressed, one of the officials said. A separate US official told CNN the threat does not involve a weapon that would be used to attack humans.It was not immediately clear whether the intelligence referred to a nuclear-powered, anti-satellite capability or a nuclear-armed capability.While members of Congress downplayed the immediacy of the threat, an anti-satellite weapon placed in orbit around Earth would pose a significant danger to US nuclear command and control satellites, said Hans Kristensen, director of the Nuclear Information Project at the Federation of American Scientists. The US relies on such satellites – which he called “essential” – to ensure constant, seamless control over its nuclear arsenal.Other countries have tested anti-satellite weapons in the past, but this would be an escalation, Kristensen said, and the US has made clear that it would react “very forcefully” to an attack on its nuclear command and control satellites.“If it’s orbital, it’s a new level of threat , whether it’s nuclear or not,” said Kristensen, who added that even conventional weapons on an orbital anti-satellite system could pose a significant threat to the U.S.ABC News first reported that the intelligence related to a Russian space-based nuclear capability.Earlier Wednesday, the chairman of the House Intelligence Committee, Republican Rep. Mike Turner of Ohio, ignited a firestorm on Capitol Hill when he issued a cryptic statement announcing that the panel had “information concerning a serious national security threat.”In a letter to lawmakers inviting them to view the intelligence in the committee’s classified spaces, he said that it related to a “destabilizing foreign military capability that should be known by all congressional policymakers.”Immediately, lawmakers began tramping down to the House basement to learn what the intelligence was.Some left underwhelmed. One Democratic member with deep national security experience said that they had never before received that kind of urgent summons over a national security matter during their time in Congress — and that the intelligence they saw when they arrived was not urgent enough to justify Turner’s alarm-pulling.Within hours, the Republican speaker of the House, Rep. Mike Johnson, attempted to tamp down the imbroglio, telling reporters that “there is no cause for alarm” and indicating that he had known about the intelligence since at least January.“We just want to assure everyone steady hands are at the wheel. We’re working on it and there’s no need for alarm,” Johnson said.Rep. Jim Himes, the committee’s top Democrat, said in a statement that “the classified intelligence product that the House Intelligence Committee called to the attention of Members last night is a significant one, but it is not a cause for panic.”National security adviser Jake Sullivan on Wednesday said he was “surprised” that Turner had made the existence of the intelligence public, noting that he was already scheduled to brief the top Republican and Democratic leaders of the House as well as Turner and Himes on Thursday.“We scheduled a briefing for the House members of the Gang of Eight tomorrow,” Sullivan said. “That’s been on the books. So I am 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 defense professionals tomorrow.”Turner in his statement has urged the Biden administration to 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.”Meanwhile, in a joint statement, the Republican and Democratic leaders of the Senate Intelligence Committee suggested that they had been tracking the intelligence but that it would be difficult to declassify it without exposing sensitive sources and methods.The uproar over the new intelligence comes as a $60 billion aid package to support Ukraine in its fight against Russia has stalled in the House and former President Donald Trump has been publicly supporting GOP members who have opposed the package. Trump has also in recent days said that he would encourage Russia to “do whatever the hell they want” to NATO allies that do not meet alliance-set spending goals on their own defense.Johnson has said that he will not bring the Senate-passed aid measure to the floor.But Turner has publicly supported continuing to fund the Ukraine war effort. Some lawmakers and US officials privately speculated that his effort to brief lawmakers on the intelligence — something the House Intelligence Committee voted on Tuesday night to do — might be an attempt to shore up flagging support for Ukraine.Sources declined to provide further detail on the intelligence or the Russian capabilities it describes.But for years, Russia has pursued counterspace systems designed to neutralize US military and commercial space systems, according to a 2022 Defense Intelligence Agency (DIA) report on space security. Russian doctrine called for being able to target an enemy’s satellites from the ground, air, cyber and space, using attacks that range from temporary jamming to outright destruction.In 2020, Russia tested a space-based anti-satellite weapon with sophisticated orbital capabilities that could have a dual purpose: it could service and inspect friendly satellites while having the capability to attack enemy satellites.An attempt to launch a nuclear-armed anti-satellite system into space would violate The Outer Space Treaty of 1967, which explicitly prohibits “any objects carrying nuclear weapons or any other kinds of weapons of mass destruction” in orbit. CNN’s Katie Bo Lillis, Alex Marquardt, Jim Sciutto, Oren Liebermann, Natasha Bertrand, Melanie Zanona and Kevin Liptak, CNN, in addition to Michael Williams, Annie Grayer and Morgan Rimmer, contributed to this report.