A U.S. ship on Tuesday rescued six Iranian mariners in the Gulf after their vessel broke down.

A U.S. ship on Tuesday rescued six Iranian mariners in the Gulf after their vessel broke down, the Pentagon said.

The Iranian crew, stuck before sunrise some 50 nautical miles (90 kilometers) southeast of the Iraqi port of Umm Qasr, used flares to seek help from the passing U.S. Coast Guard cutter Monomoy, according to the Pentagon.

The Iranian ship's master "requested assistance from the cutter indicating that the engine room was flooding and (the vessel was) not seaworthy," Pentagon spokesman George Little told reporters.

At least one of the Iranians suffered burns from a fire onboard the troubled ship and is receiving treatment from the U.S. Coast Guard, Little said.

Pentagon officials said that the United States would repatriate the Iranians, although it has not yet been determined when or how.

The United States says that its forces routinely rescue sailors in distress regardless of nationality but officials have been eager to highlight efforts to assist Iranians amid Tehran's threats to close the crucial Strait of Hormuz.

However, Tehran has neither offered confirmation nor denial for the incident.

Iran's threat -- which analysts say it may not be able to carry out -- came as the United States expanded sanctions against the Islamic Republic and the European Union considers a total ban on oil exports from Tehran.

Last week, the U.S. Navy rescued 13 Iranians held by pirates. Iran welcomed the gesture, despite its opposition to U.S. forces in the area.