As the World Cup opening ceremony got underway in Mexico, Trump posted news of a potential breakthrough, triggering a stock market rally and a drop in oil prices.

Claiming that talks with Iran had been "brought to the highest level of Iranian leadership and approved," Trump said he had "cancelled the scheduled strikes and bombings against Iran this evening."

"Time and place of the signing to be announced shortly," he promised.

He said the finer points of the arrangement had been approved by the United States and its allies in the region, including Israel, with which Washington jointly launched the war in February.

Hours after Trump's pronouncements, Iran's foreign ministry spokesman Esmaeil Baqaei said that "Iran has not reached a final conclusion on the agreement."

The Tasnim news agency noted that Trump had announced a deal was imminent 38 times in the previous two months.

"Until Iran announces the matter of a potential understanding, any news from Trump on this subject should be regarded the same as his previous messaging," it warned.

Later Trump doubled down, telling reporters "I understand the answer is yes," when asked if Iranian supreme leader Ayatollah Mojtaba Khamenei had approved the deal.

Prime Minister Benjamin Netanyahu's office said the Israeli leader spoke to Trump who vowed any memorandum of understanding would include the removal of Tehran's enriched nuclear material as well as dismantling of missile infrastructure.

The World Bank earlier in the day revised down its global growth forecast to a level not seen since the coronavirus pandemic, warning of the expanding economic impacts of the war.

- 'Approved by all parties' -

But stocks surged and oil futures dropped more than three percent after Trump's optimistic announcement.

The war -- which began February 28 with a wave of US-Israeli strikes on Iran that killed supreme leader Ayatollah Ali Khamenei -- paused under an April truce. But efforts to hammer out a permanent end to the fighting appeared stalled.

Tehran's mayor said Thursday the former supreme leader's funeral would be delayed to the end of June or start of July.

Trump's statement suggested back-channel mediation led by US allies like Pakistan and Qatar may have borne fruit -- despite previously saying he would hit Iran "VERY HARD TONIGHT."

"Discussions and final points have been, in both concept and great detail, approved by all parties involved, including the United States, Israel" and Gulf states, he posted.

Just a day earlier, he had declared that not only would US forces step up airstrikes, they would also seize control of Iran's oil export facility on Kharg Island in the Gulf.

Even as Trump's intervention raised hopes of a resolution, Kuwait reported Iran targeted its territory and damaged an airport radar forcing an airspace closure.

- Hardliners at home -

With US threats escalating, Iranian General Ali Abdollahi warned earlier in the day that if the United States attacked, "it will receive a harsher response than before, and the flames of war, in addition to creating insecurity in the region, will become more widespread and far-reaching."

Civilians facing renewed strikes in Tehran were pessimistic. Majid, a 35-year-old pharmacist, said the economic knock-on effects of the fighting were crippling normal life.

"I am absolutely not optimistic about the agreement being finalized, because the gap between the two countries is too wide," he said, blaming the lack of progress on Israel -- which also traded fire with Iran in recent days -- as well as hardliners at home.

Iran has renewed its warnings over the Strait of Hormuz, a vital waterway for oil and gas transport that it has essentially closed since early in the war, roiling global energy markets. Iran's new body overseeing the strait said it "will be closed until further notice".

burs-gw/ksb