WASHINGTON

US Secretary of State Antony Blinken called Monday on all parties in the Middle East to "take steps to ease tensions" as Iran and Hezbollah are expected to attack Israel in retaliation for the assassination of Hamas political chief Ismail Haniyeh and senior Hezbollah commander Fuad Shukr.

Speaking at a signing ceremony for a memorandum of understanding with his Australian counterpart Penny Wong, Blinken said it is a "critical moment" for the Middle East.

"We are engaged in intense diplomacy, pretty much around the clock, with a very simple message: All parties must refrain from escalation. All parties must take steps to ease tensions. Escalation is not in anyone's interest. It will only lead to more conflict, more violence, more insecurity," he said.

The top US diplomat also said it is "critical" to break this cycle by reaching a cease-fire in Gaza, which would unlock possibilities for "more enduring calm, not only in Gaza itself, but in other areas where the conflict could spread.”

"So for the United States, for many other countries, both in the region and beyond, this is our focus," he said. "And what it comes down to, really, is all parties finding ways to come to an agreement, not look for reasons to delay or to say ‘No.'"

"It is urgent that all parties make the right choices in the hours and days ahead," he stressed.

The remarks came as tensions are running high in the Middle East after Iran vowed “severe punishment” against Israel for the assassination last Wednesday of Haniyeh at his residence in the Iranian capital Tehran.

Iran's Islamic Revolutionary Guard Corps (IRGC) said Haniyeh's assassination was "designed and executed" by Israel with US support using a short-range projectile. His bodyguard was also killed in the attack.

The US announced Friday that it would deploy additional fighter jets and navy warships to the Middle East.

Hezbollah is also expected to retaliate after Israel assassinated Shukr in an airstrike on a southern suburb of Beirut on July 30.

The escalation comes amid an ongoing Israeli offensive in Gaza which has killed nearly 39,600 Palestinians following Hamas's Oct. 7 attack last year that killed 1,200 Israelis.