An Iranian drone came within 1,000 feet (300 meters) of a U.S. aircraft carrier while it was in international waters in the Gulf conducting flight operations, a spokesman for the U.S. Naval Forces Central Command said on Monday.
A drone "conducted an unsafe and unprofessional approach" as it passed by the USS Nimitz without navigation lights late on Sunday, said spokesman Lieutenant Ian McConnaughey.
Controllers for the drone did not respond to radio requests for communications, he said.
U.S. officials have complained of numerous unsafe and unprofessional interactions between the United States and Iranian maritime forces this year.
Last Tuesday, a U.S. official said an Iranian drone had approached a U.S. fighter jet as it prepared to land on the aircraft carrier. The official said at the time that it was the 13th such incident in 2017.
McConnaughey said the lack of lights on the drone in the latest incident could have caused a collision and violated "international maritime customs and laws."
The Trump administration has recently struck a hard line on Iran, saying Tehran was violating the spirit of an accord struck by the Obama administration that lifted sanctions and sought to curb Iran's nuclear aspirations.