President Joe Biden, right, talks with Israeli Prime Minister Benjamin Netanyahu, left, in the Oval Office of the White House in Washington, July 25, 2024. U.S. officials say the Biden administration believes it has won assurances from Israel that it will not strike Iranian nuclear or oil sites as it looks to strike back following Iran’s missile barrage earlier this month. The officials, who spoke on condition of anonymity to discuss private diplomatic discussions, cautioned that the pledge is not iron-clad and that circumstances could change. Associated Press File Photo

WASHINGTON — President Joe Biden is “deeply concerned” about the release of classified documents on Israel's preparation for a potential retaliatory attack on Iran, according to a White House spokesman.

U.S. officials confirmed on Saturday that the administration is investigating an unauthorized release of classified documents that assess Israel’s plans to attack Iran.

White House national security spokesman John Kirby said on Monday that the administration was still not certain if the classified information that became publicly disclosed was leaked or hacked.

Kirby added that administration officials don’t have any indication at this point of “additional documents like this finding their way into the public domain.” He added the Pentagon is investing the matter.

“We’re deeply concerned and the president remains deeply concerned about any leakage of classified information into the public domain. That is not supposed to happen and it’s unacceptable when it does,” Kirby said.

The documents are attributed to the National Geospatial-Intelligence Agency and National Security Agency, and note that Israel was still moving military assets in place to conduct a military strike in response to Iran’s blistering ballistic missile attack on Oct. 1. They were shareable within the “Five Eyes,” which are the U.S., Great Britain, Canada, New Zealand and Australia.

The documents, which are marked top secret, were posted to the Telegram messaging app.