Iran said Sunday its forces struck a U.S. unmanned vessel attempting to enter the Strait of Hormuz. The United States did not immediately confirm the reported attack.
The incident follows a U.S. military strike a day earlier on three Iranian oil tankers in direct response to a missile attack on U.S. Navy warships.
Fighting resumed last week after a period of relative calm. The broader conflict between the U.S. and Iran, which also involves Israeli attacks, began Feb. 28. A ceasefire agreement was announced in June, but negotiations between the two nations collapsed and sporadic fighting has continued.
The Strait of Hormuz and Iranian communities along its coast have again become targets. A U.S. bombardment of southern Iran earlier in the week killed at least five people.
The Trump administration has pursued a two-pronged strategy: military responses to attacks on the strait and economic sanctions targeting foreign financial institutions that facilitate Iran's transactions.
Tehran's hard-line leadership has indicated resolve to withstand these pressures. Iran has long relied on a shadow fleet to transport its oil to buyers during international sanctions.
Iran's nuclear program contributed to the conflict's outbreak. A June memorandum of understanding between the U.S. and Iran aimed at addressing the program fell apart shortly after it was signed.
Diplomats from the U.S. Britain, France and Germany are now seeking to refer Iran to the U.N. Security Council over its failure to meet nuclear nonproliferation obligations. Iran's strategic leverage centers on the Strait of Hormuz, a vital waterway for global oil and natural gas shipments.
