Australia's Foreign Minister has issued a pointed warning to Donald Trump about his 'unpredictable' approach to global diplomacy, as the US President tightens the screws on Iran despite extending a fragile ceasefire.  

Trump on Tuesday announced he would extend the ceasefire with Iran while talks between the two nations continued, but warned Washington would maintain its blockade of Iranian ports until Tehran produced what he called a 'unified proposal'.

The move underscores the US President's hardline, chaotic negotiating tactics, which Senator Wong said marked a sharp departure from how America had traditionally operated on the world stage.

'President Trump does envision a very different role for America in the world,' she told ABC Adelaide on Wednesday morning.

'We know that he prizes unpredictability. What we do need to do is continue to engage with the United States institutionally and continue to press for what we want, which is in our interests. 

'And that is the ceasefire to hold and the Strait to be open.'

Her comments come amid growing concern about the impact of ongoing tensions on global shipping routes and regional stability, with Australia watching closely as negotiations between Washington and Tehran unfold. 

Senator Wong described the ceasefire as 'fragile' and urged Iran to return to the negotiating table with the US.

'We want to see talks resume and we want to see Iran return to the negotiations. We all know that we need an end to the conflict,' she said. 

'We've been calling for that for some time.'

Senator Wong said Trump has made clear since his first term that the US no longer sees itself as underwriting the global order - a role it had traditionally embraced.

He lashed NATO after the alliance offered to assist with security in the Strait of Hormuz, despite Trump saying the situation had already been resolved.

'Now that the Hormuz Strait situation is almost over, I received a call from NATO asking if we would like some help,' the President wrote. 

'Thank you very much, NATO. I told them I would have liked your help two months ago. They were absolutely useless when we needed them. 

'We never needed them; they needed us.'

But Senator Wong was quick to defend NATO, describing it as a bedrock of peace in Europe and across the Atlantic since the end of World War II. 

'We had two world wars start in Europe. I think history tells us why it's important to maintain stability in Europe, and NATO has been central to that,' she said.

However, Senator Wong remained tight-lipped when outlining Australia's potential role in safeguarding shipping through the Strait of Hormuz should the ceasefire hold. 

'It's in the world's interest for the Strait to be opened,' she said. 'You know that 20 per cent of the world's oil goes through that Strait. 

'You probably also know that actually 80 per cent of the oil that comes to our region goes through the Strait. 

'What that means is that we and the countries of our region are disproportionately affected, which is why we have been engaging so closely with Malaysia, Singapore, Indonesia, Brunei and other countries of the region.'   

But behind the tough talk, economists say Trump is facing mounting pressure to step back, with voters increasingly uneasy about the cost of the conflict.

AMP economist Shane Oliver, who has previously described Trump as acting like a 'madman' said the pressure on the US President to back down remains high. 

He said only a third of Americans supported the war and his approval rating was below where it was eight years ago and lower than former US President Joe Biden.

'His policies, including the War, are worsening the affordability concerns that saw him elected in 2024,' he said. 'The Republicans are seeing increasing odds that they will lose both the House and the Senate in the midterms. 

'And likewise, pressure on Iran to reach a deal is high as the US switches from bombing, to even tougher economic sanctions via the blockade of Iranian oil exports will intensify popular discontent with the Iranian Government. 

'And it may conclude that its ability to cause pain for the US by effectively blocking 20 per cent of global oil supply means it has no need for nuclear weapons to ensure it survives.'