Iran's foreign minister has said his country was prepared to continue attacks for as long as necessary and ruled out talks after President Donald Trump said the war with Iran would be over "very soon".

Iranian Foreign Minister Abbas Araghchi said Monday that talks with the United States may be off the table after the U.S. and Israel initiated a military operation against the country.

The Oman-mediated negotiations follow repeated threats from Donald Trump to strike Iran, with the US president last Thursday giving Tehran 15 days to reach a deal.View on euronews

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Iran ramps up its offensive in the Gulf as tensions rise near the Strait of Hormuz, signals readiness for a potential US naval presence, and rules out talks with Washington amid the escalating conflict.

Iranian intelligence has sent word to the United States it could be prepared to open talks on how to end the war, according to people familiar with the indirect messages, but US officials say there are no negotiations currently underway and that potential “off ramps” are unlikely to materialize in the near term.

The talks sought to de-escalate tensions after Washington bombed Iranian nuclear sites and Tehran launched a bloody crackdown on nationwide protests.

How long will the Iran war last? What do all sides want to achieve? And how high will oil prices go? Big questions remain as fighting enters week two. Israel and the United States keep pounding Iran.

A top Iranian official told CNN that Tehran is prepared for a long war. Meanwhile, oil surged past $100 a barrel as the economic fallout deepens. Follow for live news updates.