“No negotiations” says Iran FM as US touts peace plan

US President Donald Trump is ready to "unleash hell" if Iran doesn't accept a deal to end the Middle East war, the White House warned Wednesday, but a defiant Tehran said it did not intend to negotiate.

The ramped-up rhetoric dashed hopes of any imminent de-escalation, as the violence on the ground showed no sign of abating after almost four weeks.

"If Iran fails to accept the reality of the current moment... Trump will ensure they are hit harder than they have ever been hit before," Press Secretary Karoline Leavitt told a news briefing, following reports that Iran had rebuffed a US peace plan.

"President Trump does not bluff and he is prepared to unleash hell. Iran should not miscalculate again," she said, while adding that "talks continue".

Iranian Foreign Minister Abbas Araghchi, however, rejected the US overture, saying "we do not intend to negotiate".

"At present, our policy is the continuation of resistance", Araghchi said on state TV, adding that the United States "speaking of negotiations now is an admission of defeat" by Washington.

Pakistani officials earlier said Islamabad had conveyed to Tehran an American 15-point plan to stop the fighting that began on February 28 with US-‘Israeli’ attacks on Iran and has since engulfed the region.

Iran state television Press TV cited an unidentified official as saying Tehran had "responded negatively" to the plan and that the war would only end on Tehran's terms, which includes guarantees against future attacks.

"We seek an end to the war on our own terms," Araghchi confirmed, "and in a way that it will not be repeated here again".

With thousands more US troops reportedly headed to the Middle East, Iran also threatened to open a new front by targeting Red Sea shipping, should the US launch a ground invasion.

“Non-hostile vessels”

With the war sending energy prices soaring, fuelling fears of higher inflation and weaker global growth, markets remained focused on the Strait of Hormuz, through which one fifth of the world's oil usually passes.

Iranian Foreign Minister Araghchi said the strait was "closed only to enemies".

"The Strait of Hormuz, from our perspective, is not completely closed -- it is closed only to enemies," Araghchi said on state TV, adding: "There is no reason to allow the ships of our enemies and their allies to pass."

He said Tehran's armed forces had already "provided safe passage" for ships from friendly nations.

Stock markets rallied and oil prices tumbled on initial reports over potential negotiations, but on Wednesday the Brent crude benchmark crept back above $100 a barrel.