The US is urging other countries through diplomatic channels to tell Iran that escalation in the Middle East is not in their interest, a State Department spokesperson says.

It follows an attack on US and coalition forces at Al-Asad Airbase in Iraq, that left at least five US personnel injured.

“We can confirm that there was a suspected rocket attack today against US and Coalition forces at Al-Asad Airbase, Iraq,” a US defence official said on Tuesday (AEST).

“Initial indications are that several US personnel were injured. Base personnel are conducting a post-attack damage assessment.”

Secretary of State Antony Blinken has called it a “critical moment” for the region and said Washington was “engaged in intense diplomacy, pretty much around the clock” to help calm tensions amid fears Iran is preparing a retaliatory strike against Israel.

“All parties must refrain from escalation,” Blinken said during a signing ceremony with Australia’s Foreign Minister Penny Wong in Washington.

“All parties must take steps to ease tensions. Escalation is not in anyone’s interests. It will only lead to more conflict, more violence, more insecurity.”

Hamas leader Ismail Haniyeh was assassinated in the Iranian capital Tehran last week, an attack that drew threats of revenge on Israel and fueled further concern that the conflict in Gaza was turning into a wider Middle East war.

Iran has blamed Israel and said it will “punish” it; Israeli officials have not claimed responsibility for the killing.

Iran backs Hamas, which is at war with Israel in Gaza, and also the Lebanese group Hezbollah, whose senior military commander Fuad Shukr was killed in an Israeli strike on Beirut last week.

Earlier, @VP and I were briefed in the Situation Room on developments in the Middle East.

We received updates on threats posed by Iran and its proxies, diplomatic efforts to de-escalate regional tensions, and preparations to support Israel should it be attacked again.

We also… pic.twitter.com/kbRcVkW3ex

— President Biden (@POTUS) August 5, 2024

US President Joe Biden and Vice-President Kamala Harris have been briefed by their national security team on the situation in the Middle East, including threats posed by Iran and its proxies to Israel and US service members, the White House said.

They were also briefed about the attack on Iraq’s al Asad airbase and discussed the US response. US officials have told Reuters at least five American personnel were wounded in the rocket strike.

It is unclear who was behind the attack or if it was linked to threats by Iran to retaliate over Haniyeh’s killing, in which the US said it had no involvement. But US officials have long blamed attacks on troops in Iraq and Syria on Iran-backed militia groups.

Biden and Harris were also updated on US efforts to support Israel militarily if it is attacked and diplomatic efforts to “de-escalate regional tension” and reach a ceasefire and hostage-release deal in Gaza.

Earlier, Blinken spoke with Qatari Prime Minister Sheikh Mohammed bin Abdulrahman Al Thani and Egyptian Foreign Minister Badr Abdelatty.

“One of the points of the engagements that we have had is to urge countries to pass messages to Iran and urge countries to make clear to Iran that it is very much not in their interests to escalate this conflict, that it is very much not in their interest to launch another attack on Israel,” State Department spokesperson Matthew Miller said.

Miller, speaking at a press briefing, did not say definitively whether or not Washington’s messages have been disseminated to Iran or through which channel.

-with AAP