The chairman of the House Intelligence Committee, Congressman Mike Turner, is demanding President Biden declassify information related to a “serious national security threat.” The national security advisor, Speaker Johnson, and other congressional leaders say there is no immediate reason for concern. 

“The House Permanent Select Committee on Intelligence has made available to all Members of Congress information concerning a serious national security threat,” Mr. Turner says in a statement. “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’s office did not immediately respond to a request for comment on the matter, but several news agencies reported that the threat comes from Russia.

Earlier Wednesday, Mr. Turner emailed colleagues to advise that his panel had “identified an urgent matter with regard to a destabilizing foreign military capability,” the Associated Press reported. The committee chairman urged colleagues to review the information in a secure area.

The national security advisor, Jacob Sullivan, says that he had planned to meet with Mr. Turner in a classified setting to discuss the matter. Mr. Sullivan, Mr. Johnson, the House minority leader, Hakeem Jeffries, and the top Democrat on the Intelligence Committee, Jim Himes, will meet on Thursday. 

Mr. Himes says there is no reason for alarm, but that the threat reported to Congress from the intelligence communities was substantial. 

“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. As to whether more can be declassified about this issue, that is a worthwhile discussion but it is not a discussion to be had in public,” Mr. Himes says. 

Mr. Sullivan said at a White House press conference that he was “surprised” that Mr. Turner decided to make this statement. 

Mr. Johnson also tells reporters that there is no reason for panic. “We are going to work together to address this matter, as we do all sensitive matters that are classified,” he says. “But we just want to assure everyone that steady hands are at the wheel. We’re working on it and there’s no need for alarm.”

The leaders of the Senate Intelligence Committee, Senators Warner and Rubio, said in a joint statement that they have been “rigorously tracking this issue from the start” but said they would not disclose the nature of the threat so as to not expose sources and methods.