The U.S. Navy halted a mission to accompany American-flagged ships passing through the Strait of Hormuz, the Pentagon announced Wednesday.
The move is being interpreted as a sign of reduced tensions in the strategic waterway.
The protection had been ordered last week after a Marshall Islands-flagged vessel was seized by Iran's Revolutionary Guard forces and a U.S.-flagged vessel was also harassed.
The order came to an end on Tuesday although U.S. warships will remain in the area to conduct "routine maritime security operations," said spokesman Colonel Steven Warren.
The U.S. Navy adjusts its mission based on its view of the conditions and there had been "several days without incident," Warren said.
The order to accompany vessels expired on Tuesday and commanders chose not to renew it, he said.
The Pentagon had previously stated that the protection mission could be extended to other countries' vessels, including British-flagged commercial ships.
Iranian authorities have said the Marshall Islands-flagged Maersk Tigris was impounded because of a commercial dispute.
It seems this explanation has satisfied Navy commanders, at least for the moment.
The Strait of Hormuz is widely regarded as the world's most important oil export route. About 30 percent of all oil traded by sea moves through the narrow body of water.
At its narrowest, the strait is just 21 miles wide, but the width of the shipping lane in each direction is only two miles, separated by a two-mile buffer zone. Given the large size of the vessels involved it makes for incredibly tight quarters.
Strategists have long worried that a miscalculation in the crowded channel could trigger a conflict.