On Monday, a White House spokesperson said President Biden was "deeply concerned" about the unauthorized release.

The FBI has opened a federal investigation over the leak of top secret U.S. intelligence documents regarding Israel's preparation for an attack against Iran. Why it matters: The leak was one of the most serious security breaches within the U.S. intelligence community in years.

American officials are trying to determine the source of the leak, which describes military drills and weapons placement, and how damaging it might be.