Iran threatened the United States with "economic warfare" on Tuesday and said it had fired an advanced missile at U.S. warships, underscoring the risks of further escalation in ​the war only days after both sides traded blows again.

The US military has struck targets near Kharg Island and the port city of Jask, Fox News reported Tuesday, part of a strategy to pressure Iran economically and bring the war to a close.

The price of Brent crude, the international standard for oil, added 67 cents, reaching $96.95 per barrel. In the U.S., the average price of regular gas was $4.14 a gallon going into Labor Day weekend, nearly a dollar higher than last year and a record for any Labor Day weekend

Tehran says time for proportionate retaliation is over after a US strike on Iranian tankers inside the blockade line.

Under economic pressure from the U.S., Iranian leaders have signaled they will not capitulate amid stunted diplomatic efforts to end the war.

Vance says gas prices could have been "much higher were it not for our efforts," as the Iran war pushes pump prices to expected Labor Day weekend records.