The United States is investigating a leak of classified documents detailing an assessment of Israel's intentions to retaliate against Iran, House of Representatives Speaker Mike Johnson confirmed. The documents were reportedly published online last week and include satellite imagery showing Israel mobilizing military assets in response to Iran's missile attack on October 1.

Marked as top secret, the documents were shareable within the Five Eyes intelligence alliance, which includes the US, Britain, Canada, New Zealand, and Australia, according to CBS News and BBC’s US partner.

In recent weeks, Israel has been deliberating on its response to Iran's missile actions, with the country’s defense minister warning that it would be “deadly, precise, and surprising.”

The leaked documents appear to originate from the US National Geospatial Intelligence Agency and the National Security Agency (NSA), having surfaced on an Iranian-aligned Telegram account last Friday. Speaker Johnson expressed his concerns during an interview with CNN, stating, "The leak is very concerning. There are serious allegations being made, and there's an investigation underway. I'll get a briefing on that in a couple of hours."

The Pentagon acknowledged awareness of the reports but declined to provide further comments. Neither US intelligence agencies nor the Israeli government have publicly addressed the leak.

Initial reports from CNN and Axios indicated that the leak suggests the US actively monitors its close ally, Israel. One of the documents alludes to Israel’s nuclear capabilities, which both the US and Israel typically do not acknowledge, seemingly ruling out the use of such options in any planned military response.

A former American intelligence official speculated that the unauthorized release might have aimed to expose the extent of Israel's planned retaliation, potentially disrupting it. The investigation is focusing on whether the leak was an intentional act by a US agent or the result of a hack, officials informed the Associated Press.

The documents are based on satellite data from October 15-16, with titles including: "Israel: Air Force Continues Preparations for Strike on Iran and Conducts a Second Large-Force Employment Exercise," detailing missile handling, and "Israel: Defense Forces Continue Key Munitions Preparations and Covert UAV Activity Almost Certainly for a Strike on Iran," discussing drone movements.

On Friday, President Joe Biden stated he had a "good understanding" of Israel's plans regarding Iran's response but did not disclose any specifics when pressed by reporters. "Yes, and yes," he affirmed when asked about his understanding, adding, "No, and no" when asked if he could share details.