The White House expressed continuing concern on Oct 21, following the apparent leak of a set of U.S. intelligence assessments of Israel’s plans to strike Iran.

“We’re deeply concerned, and the President remains deeply concerned about any leakage of classified information into the public domain,” National Security Council Coordinator for Strategic Communications John Kirby said at a Monday press call.

A social media account called Middle East Spectator first published photos of the purported U.S. intelligence assessments on Oct. 19.

The documents, which bear top-secret classified markings, describe increased Israeli handling of air-launched ballistic missile (ALBM) systems and covert drone activity. The documents state that this Israeli ALBM and drone activity is “almost certainly” indicative of Israel’s plans to strike Iran in retaliation for the Oct. 1 ballistic missile barrage Iran launched at Israel.

It’s unclear whether the documents appeared online as the result of an external hack or an internal leak.

“We’re not exactly sure how these documents found their way into the public domain. I know the Department of Defense is investigating this, and I’m sure that as they work through that, they'll try to determine the manner in which they did become public,” Kirby said.

He said President Joe Biden will “be very interested in hearing any mitigation measures and recommendations” that come as a result of the ongoing investigations.

The White House spokesman said the administration isn’t aware of any additional potential leaks but couldn’t guarantee more wouldn’t occur.

“We’re obviously keenly focused on what happened here, on learning how it happened and preventing it from happening again. And in the course of that work ... [we'll] keep our antenna up and our eyes open for any potential future disclosures,” he said.

The Israeli military did not immediately respond to a request for comment about the leaked documents.

It remains to be seen when and how Israel will strike back at Iran for the Oct. 1 missile barrage.

In the days following the Iranian missile attack, Biden indicated he had been in discussions about potential Israeli retaliatory strikes on Iranian oil facilities. At another point, the president was asked if he would support the idea of Israel striking Iranian nuclear facilities, and he responded, “The answer is no.”

Iran’s Islamic Revolutionary Guard Corps (IRGC) said it launched the Oct. 1 missile attack on Israel as retaliation for a Sept. 27 Israeli airstrike that killed Hezbollah leader Hassan Nasrallah and IRGC Gen. Abbas Nilforoushan. The IRGC said the missile barrage was also a retaliation for a July blast that killed Hamas leader Ismail Haniyeh as he visited Tehran.

Israel has not claimed responsibility for Haniyeh’s death, but Iran and Hamas have both pointed the blame at Israel.

The IRGC has insisted they remain ready with additional “heavy attacks” should Israel respond to the Oct. 1 missile attack.

Thus far, the Biden administration has affirmed that Israel has a right to respond but has also urged restraint.

“We don’t want to see any action that would lead to a full-blown regional war,” State Department spokesman Matthew Miller said at a press briefing the day after the Iranian attack.

The region has been at war since the Hamas terrorist attacks on Israel on Oct. 7, 2023, which left about 1,200 dead, thousands injured, and more than 250 abducted.