“Specifically, in the memorandum of understanding that they signed, they were not to fire on commercial vessels moving through the Strait of Hormuz. And unfortunately they have made the tragic decision — for them — to do that,” Leavitt told reporters.

The White House last month announced hostilities between the two countries would temporarily cease under the memorandum — but President Donald Trump this week formally notified lawmakers the U.S. was once again at war with Iran.

Leavitt on Thursday said Iran continues to reach out to the U.S. to negotiate a permanent ceasefire. Despite the blockade, she added, “the strait is open for ships that are not traveling to and from Iranian ports.”

“President Trump is not going to sit by and allow these active acts of terrorism to take place in the strait without ensuring Iran pays consequences for that,” Leavitt said.