US says it is sending messages to Iran that escalating hostilities is not in Tehran's interest

In the wake of a high-profile assassination in Tehran, the US has been sending messages to Iran that escalating hostilities is not in their interests and that the US will defend Israel from attacks, the State Department said on Monday.

"We have been sending consistent messages through our diplomatic engagements encouraging people to communicate to the government of Iran that escalation is not in their interests and that we will defend Israel from attacks," State Department spokesman Matthew Miller told reporters.

Miller added that escalation following last week's assassination of Hamas political leader Ismail Haniyeh would not serve Iran's interests or the interests of anyone in the region.

The US will continue to "work to try to prevent" a broader Middle East conflict from happening, he said.

"We prepare for all possibilities. That has been the case since October 7," he added, referring to last year's Hamas attack that Israel responded to with a 10-month offensive on Gaza, taking nearly 40,000 lives so far.

Miller said that Secretary of State Antony Blinken on Monday spoke to Qatari Prime Minister Al Thani and Egyptian Foreign Minister Abdullahi about tensions in the Mideast.

Blinken "delivered a consistent message in all of these engagements, we are at a critical moment for the region, and it is important that all parties take steps over the coming days to refrain from escalation and calm tensions," he said.

"The secretary is also making clear through these engagements (that) the United States continues to see a cease-fire in Gaza as the crucial step to helping calm broader tensions, in addition to, of course, securing the release of hostages and addressing the ongoing suffering of the Palestinian people in Gaza," he added.

Pressed on whether Iran has the right to self-defense after the Haniyeh assassination, Miller said: "I'm going to answer that question this way. The right is one question, what's productive is another and ultimately, we don't think it's productive or conducive to anyone's interest, including Iran's, to conduct further actions, be they retaliatory or not."

"Any further action by Iran just raises the risk of increased tensions. It raises the risk of further response from Israel or from other parties, and ultimately gets us into this position that we have worried about from the beginning, that you get a conflict that can spiral out of control," he added.