President Donald Trump said the U.S. shot down and “immediately destroyed” an Iranian drone that approached the USS Boxer near the Strait of Hormuz, the lastest sign of escalating military tensions around the critical oil chokepoint.

The drone was a threat to the ship and its crew, Trump said at the White House on Thursday. The president said he’s calling “on other nations to protect their ships as they go through the Strait.” The Boxer is an amphibious assault ship.

“The Boxer took defensive action against an Iranian drone which had closed into a very, very near distance -- approximately 1,000 yards, ignoring multiple calls to stand down and was threatening the safety of the ship and the ship’s crew,” Trump said.

Oil futures in New York clawed back a bit of the day’s 2.6 per cent loss, climbing 34 cents a barrel after the announcement.

Pentagon spokesman Jonathan Hoffman said in a statement that at 10 a.m. local time the Boxer “was in international waters conducting a planned inbound transit of the Strait of Hormuz” when a drone “closed within a threatening range” and “the ship took defensive action.”

The confrontation comes as tensions between Washington and Tehran remain high over a spate of attacks on cargo ships, the downing of an American drone and the British seizure of a tanker carrying Iranian oil.

Earlier in the day, the U.S. condemned Iranian naval activity in the Persian Gulf and demanded the Islamic Republic release a small tanker and its crew that its forces seized this week. A State Department official who asked not to be identified discussing the issue cited the Islamic Revolutionary Guard Corps’ “continued harassment” of vessels in and around the Strait.