IRAN has warned the US that any aggression will be met with an immediate response, as Washington continues to insist the nation was responsible for missiles fired at a Saudi oil refinery.

Tehran dismissed claims by US President Donald Trump and Secretary of State Mike Pompeo that Iran had been involved in the attack on Saturday, which had caused a partial halt in crude and gas production from the world’s top oil exporter.

Iran responded to the claims in a note sent to Washington via the Swiss embassy in Tehran on Monday evening, Iranian state television reported today.

It warned that any US action would be met with an immediate response which would not be limited to the source of the act of aggression.

On Saturday Yemeni armed forces conducted a large-scale operation against Saudi Arabia’s Aramco oil installations in response to the Saudi-led war on their country.

A Saudi-led bombing campaign in Yemen, which began in March 2015, has been backed by US military hardware and tactical support. Along with an illegal blockade of the port of Hodeida, it has left Yemen on the brink of the world’s worst famine in a century.

Unicef has warned that Yemen presents the largest humanitarian crisis in the world. More than 24 million people — some 80 per cent of its population — are in need of humanitarian assistance, including more than 12 million children.

Yemen’s Houthi Ansarullah movement immediately took credit for the attacks. But Mr Trump said the US was “locked and loaded” for a response at the behest of Saudi Arabia.

Iran’s Defence Minister Brigadier General Amir Hatami insisted today that the Yemeni attacks on the Saudi oil facilities were a legitimate act of self-defence.

“It’s pretty clear: there has been a conflict between two countries [Yemen and Saudi Arabia]. One party to the conflict is the Yemenis, who have said explicitly that they have done this,” he said.

As the Star went to press Mr Trump and British PM Boris Johnson stressed the need for a joint “diplomatic response.”