Israeli Defense Minister Yoav Gallant spoke on Sunday with U.S. Defense Secretary Lloyd Austin and told him Iran's military preparations suggest Iran is getting ready for a large-scale attack on Israel, Axios reported, citing a source with knowledge of the call.

The Israeli intelligence community believes Iran ma attack within days, Ravid said on Sunday, citing two sources.

The attack would be in retaliation for the killing of Hamas leader Ismail Haniyeh in Tehran in late July, Ravid added. Israel has not claimed or denied responsibility for the killing.

The urgency of the situation is underscored by the imminent ceasefire and hostage negotiations scheduled for Thursday, which Israeli officials have described as a critical "now-or-never" moment. The looming threat from Iran could severely jeopardize these pivotal talks, which are intended to address the ongoing conflict between Israel and Hamas.

According to one source, the intelligence report drafted in the past 24 hours reflects a new and heightened level of concern. Until recently, Israeli assessments suggested that Iran had not yet finalized its response, and international pressures alongside internal deliberations within Iran might lead to a postponement or moderation of their retaliation.

In a statement on Friday, Iran’s mission to the United Nations indicated a hope that any response would be carefully timed to avoid undermining the potential ceasefire.

The stakes for the coming week are high as the Biden administration seeks to broker a resolution that could prevent further escalation and secure a significant breakthrough in negotiations. The outcome of these diplomatic efforts could have a lasting impact on  Biden’s legacy and the broader stability of the region.

The situation took a setback on Sunday when Hamas rejected an invitation from the U.S., Qatar, and Egypt for a final round of negotiations on the Gaza ceasefire and hostage deal scheduled for Thursday.

Israeli intelligence remains concerned that Hezbollah, likely to retaliate first for the assassination of its top military commander, could be joined by Iran in a larger coordinated attack. The potential scale of the assault is expected to surpass Iran's previous strikes, involving missile and drone attacks targeting both military and civilian areas in central Israel.

Newsmax staffer Jack Gournel contributed.