The United States has informed Congress and its allies in Europe of new intelligence about Russian nuclear capabilities that could pose an international threat, according to officials briefed on the matter.
Officials said that the new intelligence was serious — but that the capability was still under development, and Russia had not deployed it. Consequently, it did not pose an urgent threat to the United States, Ukraine or America’s European allies, they said. The information is highly classified, and officials said it could not be declassified without cutting off its source.
A current and a former U.S. official said the new intelligence was related to Russia’s attempts to develop a space-based antisatellite nuclear weapon. ABC News reported earlier that the intelligence had to do with such a capability. Current and former officials said the nuclear weapon was not in orbit.
The threat came to light after Representative Michael R. Turner, Republican of Ohio and the chairman of the House Intelligence Committee, issued a cryptic statement calling on the Biden administration to declassify the material. Mr. Turner’s statement, and his decision to share the information with others in Congress, set Washington abuzz about what the intelligence was.
But the statement infuriated White House officials, who feared the loss of important sources of information on Russia. While Mr. Turner has been an ally to the White House on Ukraine aid, his remarks on Wednesday became the latest flashpoint in strained relations between the Biden administration and congressional Republicans.
The intelligence was developed in recent days, and while it is important, officials said it was not a break-the-glass kind of warning of any imminent threat. But Mr. Turner urged its release.
“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,” Mr. Turner said.
His committee took the unorthodox move of voting on Monday to make the information available to all members of Congress — a step that alarmed some officials, as it is not clear in what context, if any, the intelligence in the panel’s possession was presented. In a note to lawmakers, the House Intelligence Committee said the intelligence was about a “destabilizing foreign military capability.”
Capitol Hill is mired in a bitter political standoff over whether the United States should be mobilizing resources to counter Russian threats to Ukraine, a cause that most Democrats and some Republicans — including Mr. Turner — have argued is essential to protecting U.S. national security interests. But a majority of Republican members of the House, including Speaker Mike Johnson, reject calls to put a Senate-passed foreign aid package with $60.1 billion for Ukraine to a vote on the House floor.
Former President Donald J. Trump has egged on Republican opposition, saying this weekend that he would encourage Russia to “do whatever the hell they want” to any NATO country that had not spent enough money on its own defense.
Other officials said Mr. Turner was making more of the new intelligence than would ordinarily have been expected, perhaps to create pressure to prod the House to take up the supplemental funding request for Ukraine that the Senate passed this week.
That measure, providing military aid to Ukraine, Israel and Taiwan, faces an uncertain prospect in the House. While many Republicans oppose additional funding, Mr. Turner is an outspoken advocate of more assistance to Ukraine and recently visited Kyiv, the capital.
Shortly after Mr. Turner’s announcement, Jake Sullivan, the national security adviser, entered the White House press room to discuss the importance of continued funding for Ukraine’s military.
But Mr. Sullivan declined to address a reporter’s question about the substance of Mr. Turner’s announcement, saying only that he was set to meet with the chairman on Thursday.
“We scheduled a briefing for the House members of the Gang of Eight tomorrow,” Mr. Sullivan said, referring to a group of congressional leaders from both parties. “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.”
Representative Jim Himes, Democrat of Connecticut and the ranking member of the House Intelligence Committee, said the issue was “serious” and Mr. Turner was right to focus on it. But he added that the threat was “not going to ruin your Thursday.”
Senator Mark Warner, Democrat of Virginia, and Senator Marco Rubio, Republican of Florida, said in a joint statement that the Senate Intelligence Committee had been tracking the issue from the start and had been discussing a response with the Biden administration. But the lawmakers said releasing information about the intelligence could expose the methods of collection.
At the White House, when Mr. Sullivan was asked whether he could tell Americans that there was nothing to worry about, he replied that it was “impossible to answer with a straight ‘yes.’”
“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,” Mr. Sullivan said. “And we have to contend with them, and we have to contend with them in a way where we ensure the ultimate security of the American people. I am confident that President Biden, in the decisions that he is taking, is going to ensure the security of the American people going forward.”
Mr. Turner declined to respond to questions on Wednesday. Jason Crow, Democrat of Colorado, said the new intelligence was one of several “volatile threats” facing the United States.
“This is something that requires our attention,” Mr. Crow said. “There’s no doubt. It’s not an immediate crisis, but certainly something that we have to be very serious about.”
Mr. Johnson, apparently trying to spread calm after Mr. Turner’s announcement, said there was “no need for public alarm.”
“We are going to work together to address this matter,” Mr. Johnson said.
Erica L. Green , Luke Broadwater and Glenn Thrush contributed reporting from Washington.