US President Donald Trump has announced a sweeping naval operation targeting the Strait of Hormuz, one of the world’s most important oil transit chokepoints, in a move that risks deepening a global crisis and further complicating ties with Beijing in the countdown to next month’s summit.

“Effective immediately, the United States Navy, the Finest in the World, will begin the process of BLOCKADING any and all Ships trying to enter, or leave, the Strait of Hormuz,” Trump said in a social media post on Sunday.

Later in the day, US Central Command said American forces would begin “impartially” implementing the blockade against “all maritime traffic entering and exiting Iranian ports” starting on Monday at 10am ET. The measure applies to all Iranian ports along the Persian Gulf and the Gulf of Oman.

The statement added that CENTCOM forces would not impede freedom of navigation for vessels transiting the Strait of Hormuz to and from non-Iranian ports.

Trump earlier said that “at some point, we will reach an ‘ALL BEING ALLOWED TO GO IN, ALL BEING ALLOWED TO GO OUT’ basis”, but for now he had instructed the US Navy to “seek and interdict” every vessel in international waters that had paid a toll to Iran.

“No one who pays an illegal toll will have safe passage on the high seas. We will also begin destroying the mines the Iranians laid in the Straits. Any Iranian who fires at us, or at peaceful vessels, will be BLOWN TO HELL!”

The announcement was part of a barrage of remarks issued after 21 hours of talks between the United States and Iran in Pakistan ended without an agreement.