TEHRAN, Iran — Iran displayed an aircraft Thursday that it said was a U.S. spy drone brought down by an "electronic ambush," a feat that prompted boasts of Iranian technological prowess in the face of increased hostility from the West.

The images were presented as the first visual proof that Iran has the radar-evading batwing aircraft, which appeared in the video to be in good condition. It was displayed on a platform decorated with a banner saying "We'll trample America underfoot" and a U.S. flag with skulls instead of stars. The authenticity of the video could not be verified.

Pentagon officials would not confirm whether the aircraft in the video was a U.S. drone. Other officials said privately that the aircraft resembled an RQ-170 Sentinel, the kind of drone that Iran said Sunday had been brought down after it violated the country's airspace.

U.S. experts were studying the Iranian video, officials said, adding that the drone the United States acknowledged it lost control of late last week was still not back in U.S. possession.

"We haven't recovered the drone that we believe is missing," said Navy Capt. John Kirby, a Pentagon spokesman.

Iran's armed forces said Sunday that their electronic-warfare unit managed to take control of a Sentinel and steer it to the ground, a feat U.S. officials say is unlikely because of its difficulty. The aircraft was detected over the eastern town of Kashmar, about 140 miles from the border with Afghanistan, Iranian media reported.

A senior U.S. official said the drone was on a mission for the CIA, raising fears that its sophisticated technology could be exploited by Iran or shared with other U.S. rivals.

Iranian officials have seized on the incident to promote the prowess of their armed forces at a time of deepening diplomatic isolation and growing Iranian anger over the Western campaign to stop the country's nuclear program. The United States and its allies accuse Iran of working to develop an atomic weapon, a charge denied by Iranian officials, which maintain that the nuclear program is for civilian purposes. Esmail Kosari, deputy speaker of the Iranian Parliament, described the reported downing of the drone as a "blow to the arrogant power" of the U.S.

Iran's Foreign Ministry summoned the Swiss ambassador Thursday to protest "the violation of its airspace," the official Islamic Republic News Agency reported. The U.S. does not have diplomatic representation in the country, so its affairs are handled by the Swiss envoy.

Material from The Washington Post is included in this report.