Washington — President Trump said Wednesday he has ordered the U.S. Navy to take action against Iranian vessels that "harass" U.S. ships at sea.

"I have instructed the United States Navy to shoot down and destroy any and all Iranian gunboats if they harass our ships at sea," Mr. Trump said in a tweet.

No further information was given by the president or the White House regarding his directive.

I have instructed the United States Navy to shoot down and destroy any and all Iranian gunboats if they harass our ships at sea. — Donald J. Trump (@realDonaldTrump) April 22, 2020

Mr. Trump's instruction, however, comes a week after 11 ships with Iran's Islamic Revolutionary Guard Corps Navy "repeatedly conducted dangerous and harassing approaches" of U.S. ships in the North Arabian Gulf, according to the 5th Fleet.

Get Breaking News Delivered to Your Inbox

The 5th Fleet said the Iranian vessels "repeatedly crossed the bows and sterns" of the American ships "at extremely close range and high speed" and called the actions "dangerous and provocative." In one instance, an Iranian ship came within 10 yards of a U.S. vessel's bow.

Iranian gunboats have harassed U.S. and other allied ships in the Gulf for years, particularly around the strategically pivotal Strait of Hormuz, through which a third of the world's oil supply travels. The U.S. blamed Iran for a series of attacks on oil tankers in the Gulf in 2019, setting off a series of escalations that threatened to expand into a full-blown regional conflict.