WASHINGTON: Two Iranian fighter jets fired on an unarmed U.S. drone in the Gulf last week and missed, the Pentagon said Thursday, warning that the United States stood ready to protect its forces in the region. The incident occurred on Nov. 1, but the Pentagon kept it quiet until now.

“They intercepted the aircraft and fired multiple rounds,” spokesman George Little told a news conference.

The confrontation threatened to ignite a potential conflict between the arch foes amid a mounting crisis over Tehran’s nuclear program and a shadow war marked by cyberattacks and assassinations in Iran.

Tough new sanctions led by the United States are squeezing Iran’s economy while Washington is accused of staging cyber sabotage on Tehran’s uranium enrichment plants.

The U.S. military drone was “never in Iranian airspace” and came under fire from Su-25 fighters off the Iranian coast over international waters, Little said.

The robotic Predator aircraft was conducting “routine surveillance” and the United States has told Iran it has no plans to suspend the flights, he said.

“The United States has communicated to the Iranians that we will continue to conduct surveillance flights over international waters over the Arabian Gulf consistent with longstanding practice and our commitment to the security of the region,” he said.

In a warning to Tehran, the Pentagon spokesman said the United States was prepared to safeguard its forces.

“We have a wide range of options, from diplomatic to military, to protect our military assets and our forces in the region and will do so when necessary,” Little said.

The Predator returned safely to an unspecified military base in the region following the incident that occurred at 8:50 a.m. GMT.

The MQ-1 drone, a turboprop plane that flies at a much slower speed than the fighter jets, was pursued further by the Iranian warplanes but not fired on again, Little added.

The Predator was intercepted about 16 nautical miles off the Iranian coast, beyond the Islamic Republic’s territorial waters that extend 12 nautical miles off the country’s shore.