US President Donald Trump announced that the United States and Iran had completed a deal that would reopen the Strait of Hormuz and end the US naval blockade, marking what he described as a major breakthrough after months of conflict that rattled global energy markets and raised fears of a wider regional war.

“The Deal with the Islamic Republic of Iran is now complete. Congratulations to all!” Trump said in a post on social media.

The announcement came as international attention remained focused on the narrow waterway through which a substantial portion of the world's seaborne oil trade passes. The Strait of Hormuz has been at the centre of tensions between Washington and Tehran for months, with disruptions to shipping contributing to volatility in global energy prices.

Trump said he was authorising the reopening of the waterway and lifting the US blockade that had been imposed during the conflict.

“I hereby fully authorize the toll free opening of the Strait of Hormuz, and, simultaneously herewith, authorize the immediate removal of the United States Naval blockade,” he wrote.

“Ships of the World, start your engines. Let the oil flow!”

In a second post, Trump cast the agreement as a historic diplomatic achievement.

“This Great Deal will bring Peace and Security to the whole Region,” he wrote.

“Many presidents have tried to make Peace with Iran, and all have failed before me.”

“The Leaders of the Region have, for the first time, found a President who can help them achieve real Peace,” he added.

Trump said the agreement would be formally signed on Friday and linked the reopening of the Strait to efforts to remove mines from the waterway.

“With the opening of the Strait upon the signing of the Deal on Friday, for purposes of mine removal, oil will flow on both ends again for the Region, and the World!” he said.

The President did not disclose details of the agreement, and no official text was immediately released by the White House. His posts also did not address broader issues that have long divided Washington and Tehran, including Iran’s nuclear programme and US sanctions.

However, Trump's statements suggested that the immediate focus of the agreement is restoring freedom of navigation through the Strait of Hormuz and removing barriers to commercial shipping.

The announcement followed a day of intense diplomatic activity. Several international news organisations reported that US and Iranian negotiators had moved closer to an understanding after weeks of negotiations involving regional mediators.

According to reporting by The Wall Street Journal, US and Iranian officials had indicated that a formal signing ceremony was expected later this week and that reopening the Strait of Hormuz and lifting the naval blockade formed the core of the arrangement.

The newspaper reported that the two sides had agreed on an interim framework aimed at ending hostilities and creating space for further negotiations.

The Washington Post similarly reported that the agreement would end the US blockade and reopen the Strait while leaving other major issues for future negotiations. The newspaper said discussions on Iran’s nuclear programme and sanctions relief were expected to continue in a separate phase of talks.

The New York Times reported that the agreement was expected to halt fighting, reopen the Strait and remove the naval blockade while deferring more contentious questions to future negotiations. The newspaper described the accord as a cease-fire arrangement that could pave the way for broader talks between the two countries.

Trump presented the agreement as evidence that his administration had succeeded where previous US presidents had fallen short.