Trump said the negotiations are intended to secure the immediate reopening of the Strait of Hormuz and to address concerns about Iran's nuclear programme.

Speaking to reporters aboard Air Force One, Trump said Iran had been aware of the scale of the planned military action and had sought to avoid an attack.

"Right now, we are talking to them as part of negotiations," Trump said, adding that the talks would begin on Monday afternoon, but without providing further details.

Neither Iran nor the countries mediating the conflict have officially confirmed whether the negotiations will take place.

However, Iran announced on Sunday that it was close to an agreement with Oman over the Strait of Hormuz, a vital global energy shipping route, although Iranian officials said the discussions were unrelated to reopening or closing the strategic waterway.