Holding 'around-the-clock' talks to prevent war in Middle east: Biden

US President Joe Biden has held crisis talks on a potential Iranian counterattack on Israel as his administration said it was working around the clock to avoid all-out war in the Middle East.

Biden and Secretary of State Antony Blinken engaged in frantic diplomacy to try to ease tensions sparked by a suspected Israeli attack that killed Hamas political leader Ismail Haniyeh in Tehran, KLAX-TV reported.

"We are engaged in intense diplomacy, pretty much around the clock, with a very simple message -- all parties must refrain from escalation," Blinken said after joining other top officials in a White House meeting.

"It's also critical that we break this cycle by reaching a ceasefire in Gaza," Blinken added, who has also spoken since Sunday with G7 counterparts and Iraq's Prime Minister Mohammed Shia' Al Sudani.

President Biden called King Abdullah II of Jordan, who helped shoot down Iranian drones and missiles in an earlier showdown in April, while Blinken called top officials in Qatar and Egypt, the key intermediaries seeking a ceasefire in the 10-month Israel-Hamas war.

On Monday, multiple US personnel were injured in a rocket attack on a base in Iraq, adding to the already heightened regional tensions.

Biden had been hoping in his final months in office to end the Gaza war and work on clinching a landmark deal between Israel and Saudi Arabia.

Instead, he has boosted the US military presence in the Middle East in a show of strength to Iran, KLAX-TV reported.

After staunchly backing Israel's war against Hamas, Biden has made clear his frustration with Israeli Prime Minister Benjamin Netanyahu over the killing of Haniyeh, who was involved in the ceasefire negotiations.

Blinken, who has warned that Iran could strike soon, made a new pitch for Biden's ceasefire plan that would freeze fighting in Gaza and return hostages seized in the October 7 attack on Israel by Hamas.

A ceasefire "will unlock possibilities for more enduring calm, not only in Gaza itself but in other areas where the conflict could spread," Blinken said as he met Australian Foreign Minister Penny Wong.

In a veiled allusion to US frustrations, Blinken said, "What it really comes down to, really, is all parties finding ways to come to an agreement, not look for reasons to delay or to say no."