The move followed the collapse of weekend talks between Washington and Tehran, prompting President Donald Trump to say on Sunday the US navy would enforce a blockade targeting vessels entering and leaving Iranian ports, even as Washington stressed it would not restrict transit through the strait itself.

Trump’s announcement effectively ​slowed oil tanker movements in the strait, with just two Iranian-linked tankers leaving the Gulf.

In normal trading conditions, crude and products loaded ​from Iranian ports are typically headed for China, with India a recent buyer of Iranian crude.

The tanker Auroura ⁠is laden with Iranian oil products, while the New Future vessel is carrying diesel loaded from the Hamriyah port in the United Arab Emirates and ​is heading to Sohar, Oman, Kpler and LSEG data showed. Both are medium-range tankers carrying about 330,000 barrels of oil.

US Central Command said US forces ​would begin implementing the blockade of all maritime traffic entering and exiting Iranian ports at 10am on Monday.

It would be “enforced impartially against vessels of all nations entering or departing Iranian ports and coastal areas, including all Iranian ports on the Arabian Gulf and Gulf of Oman,” it said in a statement on X.

US ​forces would not impede freedom of navigation for vessels transiting the Strait of Hormuz to and from non-Iranian ports, and additional information would be ​provided to commercial mariners through a formal notice prior to the start of the blockade, it said.

Iran’s Revolutionary Guards said on Sunday that any military vessels attempting to ‌approach the ⁠Strait of Hormuz would be considered a violation of the ceasefire and be dealt with harshly and decisively.

Liberia-flagged very large crude carrier (VLCC) Mombasa B, which transited the strait earlier on Sunday, is sailing empty in the Gulf and heading to Basra, Iraq, according to the data.

Malta-flagged VLCC Agios ​Fanourios I, which attempted to enter the Gulf on Sunday to load Iraqi Basra crude for Vietnam, ​has since turned back ⁠and is anchored near the Gulf of Oman, the data showed. The tanker plans to head to Iraq.

Eastern Mediterranean Maritime, which manages Agios Fanourios I, did not respond to a request for comment.

Despite the stalemate, three supertankers fully ​laden with oil passed through the Strait of Hormuz on Saturday, shipping data showed.

They appeared to be the first vessels to exit the Gulf since the ceasefire deal was struck ​last week.