Iran's Foreign Ministry summoned the Swiss ambassador, who represents U.S. interests in the country, to condemn what it said was a U.S. violation of its airspace, state television reported on Thursday.
Iran's military said on Sunday it had shot down a U.S. reconnaissance drone in eastern Iran. An official in the U.S. said there was no indication the aircraft had been shot down.
NATO's U.S.-led mission in neighboring Afghanistan said the Iranian report could refer to an unarmed U.S. spy drone that went missing recently.
"Iran's Foreign Ministry summoned the Swiss ambassador on Thursday and strongly objected to America's violation of the country's airspace with a spy drone - Iran also demanded the American government's explanation and compensatory action," Iranian television said.
Washington has not had a mission in Iran since 1980, when Iranian students stormed its embassy and took 52 Americans hostage for 444 days.
The drone incident comes at a time when Tehran is trying to contain foreign outrage at an attack on the British embassy last week, after London imposed sanctions on Iran's central bank over Iran's disputed nuclear enrichment program.
Iran's state television showed pictures of the drone with an American flag hanging from it.
"With God's help, we were able to bring down one of America's most advanced planes... with minimal damage," Revolutionary Guards Commander Ali Hajizadeh told state television, standing in front of the drone. Iran has announced several times in the past that it shot down U.S., Israeli or British drones, in incidents that did not provoke high-profile responses.
Tehran is at loggerheads with Washington and its allies over the Islamic state's disputed nuclear program, which the West suspects is aimed at making nuclear weapons.
Iranian officials deny the charge, saying the country wants nuclear technology to generate electricity.
The United States and Israel have not ruled out military action against Iran's nuclear facilities if diplomacy fails to resolve the row. Iran has said it would respond to any strike by attacking Israel and U.S. interests in the Gulf.
In January Iran said it shot down two unmanned Western reconnaissance drones in the Gulf. In July Iran said it had shot down an unmanned U.S. spy plane over the holy city of Qom, near its Fordu nuclear site.
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