The Iranian ambassador to Australia was asked six times whether the Islamic regime is plotting to build a nuclear weapon but failed to give a direct answer until the final query.

Ahmad Sadeghi was grilled by Insiders host David Speers on the ABC's 7.30 program on Wednesday night about the theocracy's alleged plans to build nuclear warheads amid the escalating Israel-Iran conflict. 

It came after planned talks between Iran and the United States were scrapped last week when Israel launched what it called 'pre-emptive' missile strikes on Tehran. 

Israel's Prime Minister Benjamin Netanyahu said they were striking 'at the heart of Iran's nuclear weaponisation program', as the region now teeters on the brink of all-out war. 

'Has Iran been working on plans for a nuclear weapon?', Speers asked the ambassador. 

Sadeghi insisted any nuclear facilities in the regime complied with the 'safeguard measures' imposed by the International Atomic Energy Agency (IAEA).

But Speers pointed out that last week the IAEA board of governors passed a resolution stating that Iran was in breach of its obligations under the Nuclear Proliferation Treaty.

Sadeghi prevaricated, claiming Iran's engagement with the IAEA was an ongoing process.

But Speers was having none of it. 

'Can I come back to the question though: was Iran working towards a nuclear weapon?'

'Iran declared quite a few times that it does not have any nuclear ...programs in terms of military aspects,' Sadeghi mumbled.

Speers shot back: 'Can you say today that Iran is not working towards a nuclear weapon?'

'(It) has not done it...yet,' Sadeghi responded.

Speers seized on the word 'yet', asking if that was the eventual plan - as Israeli intelligence has been suggesting for years. 

Sadeghi then shifted uncomfortably in his seat. 

On the sixth occasion of being asked whether Iran was planning to build a nuclear weapon, he finally said: 'Of course not, you know it has been prohibited by our supreme leader.'

Iran's Supreme Leader, Ayatollah Ali Khamenei, posted on X yesterday: 'The Zionist enemy has made a grave mistake and committed a serious crime, and it must be punished.'

Sadeghi insisted Iran's nuclear capability was a 'peaceful program' and condemned Israel as the 'aggressor' in the conflict.

He said Iran would only come to the negotiating table if Australia condemned Israel's actions.   

'When it comes to the Australian position, we ask Australia … a friendly nation … to condemn,' he said.

On Thursday morning, Foreign Minister Penny Wong hardened Australia's stance against Iran, claiming the regime has a 'choice' and calling for it to 'discontinue any nuclear program'.   

'It's time - beyond time - for Iran to come back to the negotiating table, for Iran to agree to discontinue any nuclear program,' Senator Wong told ABC News Breakfast.

'It is in the interests of the Iranian people and in the interests of the people of the region for Iran to return to dialogue and diplomacy.

'Iran has a choice here… And the choice should be to return to the table and engage in dialogue and diplomacy. It must stop any production of nuclear weapons.'

Israel took a veiled swipe at Senator Wong earlier this week when she called for the two countries to 'return to diplomacy and dialogue'.

Israel's initial strike has been followed by repeated exchanges of fire between both countries, leaving casualties on both sides.

However, Iran has taken the brunt of the damage with Israel's 'Iron Dome' blocking most Iranian rockets. 

Donald Trump left the G7 summit in Canada early this week to return to Washington to deal with the escalating conflict. 

It is understood that the US President has approved plans for a US attack on Iran, although he has not given the go ahead to carry them out.

Trump met with his top generals in the Situation Room on Wednesday night as details on a potential US offensive were discussed.