U.S. forces struck three Iranian oil tankers after Navy warships came under ballistic missile attack, the American military said Saturday.

It warned it would "if necessary, destroy Iran's limited and exposed oil fleet."

Experts called the move a dangerous escalation after Iran's earlier attacks at sea had targeted commercial shipping.

The strikes came a day after President Donald Trump described the conflict as "small potatoes."

They mark a return to fighting after six months of on-and-off war that began with U.S. and Israeli attacks on Iran on Feb. 28.

The military said an American aircraft carrier and a destroyer evaded "multiple unprovoked Iranian attacks," and no U.S. personnel were hurt.

Two Iranian oil carriers were "permanently disabled," and a third, unladen one, was destroyed.

Iran's joint military command warned that strikes against U.S. military ships would be more severe if the U.S. keeps interfering with Iranian shipping, state media reported.

Danny Citrinowicz, an Iran expert at Israel's Institute for National Security Studies, said the missile attack on a U.S. carrier showed Tehran was accepting risks it previously avoided.

The U.S. said one tanker was hit off Kharg Island, another near Jask, and the unladen one in the Gulf of Oman, where its crew was told to abandon ship.

The latest strikes came nearly a week after the U.S. and Iran resumed attacks following a month of calm.

At least five people were killed earlier in the week during a U.S. bombardment of southern Iran, including one strike that hit a wedding.

Two teenage girls wounded in that attack described explosions and injuries in hospital interviews.

The Trump administration has combined military responses with pressure on foreign financial institutions handling Iran's money, while Vice President JD Vance said talks were unlikely while Iran targets ships.