The FBI has launched an investigation into the illegal release of classified documents detailing Israel's preparations for a potential retaliatory strike against Iran.
White House national security spokesman John Kirby said there was no immediate confirmation whether the information had been leaked or hacked.
He stressed that there is currently no indication that additional documents will be made public, The Wall Street Journal writes.
The FBI first announced it was investigating the leak of classified documents on Tuesday.
The service said in a statement that it cooperates with the Ministry of Defense and intelligence.
The FBI did not provide further comment on the case.