US forces have conducted what Washington called defensive strikes in southern Iran, the latest escalation in the war between the two nations.

Describing the strikes against targets including boats attempting to lay mines and missile launch sites, Secretary of State Marco Rubio said the Strait of Hormuz has ⁠to be open “one way or the other.”

“The straits have to be open, they’re going to be open one way or the other, so they need to be open,” Rubio told reporters on a trip to India.

Despite a ceasefire in place since early April, US Central Command said in a statement on Monday it had carried out fresh strikes designed “to protect our troops from threats posed by Iranian forces.”

The U.S. attacks came ​as ⁠Iran’s top negotiator and its foreign minister were in Doha for talks with Qatar’s prime minister on a potential deal with the US to end the three-month-old war, an official briefed on the visit said.