Fears grew Monday that the U.S.-Iran truce could collapse after Washington said it seized an Iranian cargo ship attempting to breach its blockade and Tehran vowed to retaliate.
Efforts to build a more lasting peace in the region also appeared under threat, as Iran said it would not participate in a second round of negotiations that the U.S. had hoped to kick off before the cease-fire expires.
The U.S. has maintained a blockade of Iranian ports while Iran has lifted and then reimposed its own blockade on marine traffic passing through the Strait of Hormuz, which typically handles roughly one-fifth of the world's oil supply.
The U.S. military said it fired on an Iranian-flagged cargo ship headed towards Iran's Bandar Abbas port Sunday after a six-hour standoff, disabling its engines.
U.S. Marines then rappelled from helicopters onto the vessel, U.S. Central Command said.
