Secretary of State Antony Blinken, in what he said was a "critical moment," called on parties in the Middle East to work to ease tensions as fears of a larger regional war mount after the killings last week of a senior Hezbollah commander in Lebanon and Hamas' top political leader in Iran.

"We are engaged in intense diplomacy, pretty much round-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 interests," he said at a signing ceremony with his Australian counterpart. "It will only lead to more conflict, more violence, more insecurity."

Blinken added, "It's also critical that we break this cycle by reaching a cease-fire in Gaza, and that in turn, will unlock possibilities for more enduring calm, not only in Gaza itself, but in other areas where conflict could spread." He called on all parties to find "ways to come to an agreement, not look for reasons to delay or say 'no,'" and added, "It is urgent that all parties make the right choices in the hours and days ahead."

His comments came after President Biden convened the national security team in the Situation Room to discuss developments in the Middle East earlier in the afternoon. Mr. Biden also spoke with King Abdullah II of Jordan Monday, and according to a readout from the White House, the two leaders discussed their efforts to de-escalate regional tensions, including through an immediate cease-fire and hostage release deal. Over the weekend, the Jordanian foreign minister made a rare visit to Iran.

Top military leaders from the U.S. and Israel met In Tel Aviv Monday as fears of a larger regional war mount following the killings last week of a senior Hezbollah commander in Lebanon and Hamas' top political leader in Iran.

U.S. CENTCOM Commander Gen. Michael Erik Kurilla met with Israeli defense minister Yoav Gallant and Israel Defense Force Chief of the General Staff Lt. Gen. Herzi Halevi to discuss "the coordination of defense cooperation between the respective establishments and militaries," according to an Israeli readout of the meeting. The Defense Department did not release a U.S. readout.