Sources: Russia provides Iran with intelligence that could allow attacks on U.S. forces

The intelligence concerns the positions of US warships and aircraft in the Middle East, officials say.

"It seems to be a fairly extensive effort," says one of the people.

US Secretary of War Pete Hegseth said on Wednesday that Russia, the US's main nuclear-armed competitor, is "not really a factor" in the war.

The Russian Embassy in Washington has not responded to a request for comment.