It was the second such action this week, as the Trump administration ramps up pressure on Tehran.
The killing of Ayatollah Ali Khamenei ushered in a new form of collective leadership in the country, with more power for the Revolutionary Guards.
A British naval agency said the two vessels had come under attack near the strait, as a U.S. blockade on Iran’s ports continued.
The United States has halted dollar shipments to Iraq’s cash-based economy in an effort to force the Baghdad government to distance itself from Iran. The money comes from Iraq’s oil revenues.
The Treasury secretary said that currency swap line would benefit both the United Arab Emirates and the United States.
President Trump has ridiculed President Barack Obama and the agreement, which he withdrew from during his first term. His critics say he could have avoided a war had he left it in place.
With the cease-fire on the verge of ending, President Trump said on Tuesday that he would keep it in place until Iran’s “proposal is submitted, and discussions are concluded, one way or the other.”
Washington is demanding that the Baghdad government dismantle Iran-backed Iraqi militias that have been attacking Americans and U.S. sites there recently.
The delay is another hurdle in the Trump administration’s push to secure an agreement that would curb Iran’s nuclear program.
President Trump attributed his decision to divisions among the Iranians about how to proceed and said he wanted to give them more time.