President Donald Trump has paused attacks on Iran for the third night in a row to give diplomacy more time, the US ambassador to the UN said.

Speaking to Fox News on Sunday, ambassador Mike Waltz said the president was "giving talks some space, he's giving it a little bit of room".

An Iranian army spokesperson said on Sunday that Tehran had halted "retaliatory" attacks in the region in response. The pause follows nearly two weeks of daily US strikes and tit-for-tat attacks, effectively unravelling the ceasefire struck in June.

Oil prices have dropped sharply in the wake of the pause,falling below $90 per barrel on Monday morning after hitting $100 for the first time since May last week.

Asked whether Trump had decided against escalation for now, Waltz told NBC: "I wouldn't go that far at all. The president is keeping all options on the table."

Waltz also rejected reports in the New York Times that administration officials had warned expanding hostilities could dangerously drain a diminished stockpile of air defence munitions.

"The US military... has everything that it needs to conduct this campaign as effectively as it needs to be," he said.

Speaking to CBS, he added: "We'll see over the next coming days. But make no mistake, additional military assets are moving into the region."

"The regime should believe the president when he says they're locked and loaded, and where all options are on the table."

As of Monday, Trump had not spoken publicly on the latest developments, but earlier posted computer-generated images on his Truth Social account that depicted US military planes bombing Iranian ships and Kharg island.

The pause follows 13 consecutive nights of US strikes on Iran, which Washington said aimed to "degrade Iran's ability to threaten commercial shipping in the Strait of Hormuz."

Meanwhile, Iran and Oman held several rounds of technical talks in Tehran on Friday and Saturday to discuss management of the Strait of Hormuz, according to Iranian foreign ministry spokesman Esmail Baghaei.

Disputes over control of the strait reignited US-Iran tensions earlier this month and it remains a major block to permanently ending the war.

Iran and the US signed a memorandum of understanding in June to halt military operations and reopen the strait, as well as to reach an agreement to end the war over the following 60 days.

But after Iranian forces attacked tankers in the Strait of Hormuz on 13 July, the US resumed airstrikes on the country and reinstated its naval blockade on Iranian ports.

Iran retaliated with attacks on US military facilities and bases across the Middle East, killing four American soldiers. The US strikes have since killed dozens of people, according to Iran's health ministry.

In the UK, new Defence Secretary Wes Streeting said he would meet his US counterpart Pete Hegseth in the coming week to discuss the strait, which is one of the world's key transport routes for oil, liquid natural gas and other essential commodities.

"When it comes to securing maritime freedom and free commercial shipping in the Strait of Hormuz, that's where we are absolutely aligned," Streeting told the BBC.

Last week, oil prices hit $100 a barrel for the first time since May, as the renewed fighting stoked fears over global energy supplies.

As the war nears its fifth month, it remains largely unpopular in the US, with a new poll from CBS/YouGov suggesting 57% of Americans are frustrated about the conflict and only 19% optimistic.

Thousands of people have been killed across the Middle East since the US-Israeli war with Iran began in February, official figures show, with the vast majority coming from Iran and Lebanon.

President Trump is set to meet Israeli Prime Minister Benjamin Netanyahu in the White House on Tuesday.