The US is aiming “to turn the temperature down” in the Middle East, the country’s ambassador to the UN has said, after Iran dismissed calls from Western countries to refrain from retaliating against Israel for the assassination of Hamas’ leader last month.

On Tuesday, Linda Thomas-Greenfield told the UN Security Council in New York the US wanted to “deter and defend against any future attack and avoid regional conflict”.

Her comments came as the US stepped up its efforts to reach a ceasefire between Israel and Hamas in Gaza.

Asked by a reporter whether reaching such a deal would help deter Iran from launching attacks on Israel, US President Joe Biden said: “That’s my expectation but we’ll see.”

“We’ll see what Iran does and we’ll see what happens if there’s any attack, but I’m not giving up,” he said, while exiting his plane during a visit to New Orleans, Louisiana on Tuesday.

A new round of ceasefire talks is scheduled to take place in either Doha or Cairo on Thursday.

But Hamas official Ahmad Abdul Hadi has reportedly said Hamas will not take part in the talks, according to reports by the New York Times and Sky News.

US Secretary of State Antony Blinken postponed plans to travel to the Middle East on Tuesday to participate in negotiations on ending the war in Gaza.

International mediators from the US, Egypt and Qatar have been pushing for a ceasefire deal that would see Israeli hostages released to their families and Palestinian civilians returned to their homes.

Meanwhile, Washington has also approved a shipment of arms sales worth $20bn (£15.5bn) to Israel – the arms will take years to reach Israel.

At the Security Council meeting in New York, Ms Thomas-Greenfield called for a ceasefire deal to be finalised.

“A broader regional conflict is not inevitable,” she said.

“The United States’ overall goal remains to turn the temperature down in the region, deter and defend against any future attacks, and avoid regional conflict,” she added.

“That starts with finalizing a deal for an immediate ceasefire with hostage release in Gaza. We need to get this over the finish line.”

But Palestinian ambassador to the UN, Riyad Mansour, accused the Security Council of not doing enough to stop Israel’s military operation in Gaza.

“Wake up. Stop finding excuses. Stop imagining that you can reason with the Israeli government so it stops killing civilians by the thousands, imposing famine, torturing prisoners, colonising and annexing our land, all while you appeal to them, call on them, demand them to stop,” Mr Mansour said.

Israeli ambassador Gilad Erdan claimed Hamas used civilians as human targets in Gaza.

Israel launched a military campaign in Gaza to destroy Hamas in response to an unprecedented attack on southern Israel on 7 October, during which about 1,200 people were killed and 251 were taken hostage.

More than 39,920 people have been killed in Gaza since then, according to the territory’s Hamas-run health ministry.

Hundreds of people have also been killed in the almost daily exchanges of fire between Hezbollah and the Israeli military across the Israel-Lebanon border since the day after the start of the conflict.

Amid a flurry of international diplomacy to de-escalate tensions, Iran on Monday dismissed calls from the UK and other Western countries to refrain from retaliation against Israel for the killing of Hamas leader, Ismail Haniyeh.

Israel, which did not say it was involved in Haniyeh’s assassination, has meanwhile put its military on its highest alert level.

The US has warned that it is preparing for “a significant set of attacks” by Iran or its proxies as soon as this week, and has built up its military presence in the Middle East to help defend Israel.