Iran sparked chaos in the Middle East last night when it announced it was closing the Strait of Hormuz again over Israel's continuing attacks on southern Lebanon.

The Iranian military said it was shutting the vital shipping channel because Israeli strikes – which killed 16 people yesterday – had violated the US-Iran peace deal.

Iran's Revolutionary Guards (IRGC) warned vessels to stay away from the Strait, which it had agreed to keep open as part of the agreement.

It was not clear on Saturday night if the Strait was closed. The IRGC issued a statement on Iranian state television saying the closure was 'the first step in response to the enemy's breach of promise'.

It warned that 'if the aggression continues, further steps will be taken to force the enemy to comply with its obligations'.

In response, the US military said its forces remained 'present and vigilant to ensure all aspects of the agreement with Iran are adhered to, obeyed and in full force and effect'.

In an apparent 11th-hour intervention, possibly under pressure from Donald Trump, Israel's prime minister Benjamin Netanyahu last night ordered his military to 'hold fire'.

Israeli news channels said the move followed 'co-ordination' with the US.

In 24 hours of rapidly evolving developments, further talks in Switzerland between the two sides were still said to be going ahead today.

Pakistan confirmed the postponed technical-level talks would begin in Burgenstock.

Iran's foreign ministry spokesman Esmaeil Baghaei said a delegation would be travelling to the talks to 'demand implementation of the other party's commitments'.

The delegation had originally been expected to travel for talks and a signing ceremony of the memorandum of understanding on Friday, but these were cancelled, with Tehran blaming Israeli actions.

US Vice-President J.D. Vance appeared oblivious to the threatened closure on Saturday night, saying there was 'no evidence' the strait was shut.

He told Fox News that pre-war levels of oil had moved through the strait – 16million barrels in 24 hours.

'That is basically to where it was before the war, so that suggests that the straits really are open,' he commented.

Mr Vance said he was confident the ceasefire agreed in last week's 14-point deal would hold.

An end to fighting between Israel and Iran-backed Hezbollah in Lebanon is a condition of the ceasefire.

This was said to have started on Friday afternoon, but both sides accused the other of offensive action, with Israel saying Hezbollah had launched missiles at its forces that night.