(CNN) -- Iran will not return an unmanned American stealth plane that it says it has, one of Iran's top generals said, according to the semi-official Fars news agency on Sunday.
"No nation welcomes other countries' spy drones in its territory, and no one sends back the spying equipment and its information back to the country of origin," said Gen. Hossein Salami, deputy commander of the Armed Forces.
"It makes no difference where this drone originated and which group or country sent it to invade our air space," Salami said. "This was an act of invasion and belligerence."
American officials have not confirmed that the drone in a video released Thursday is a U.S. aircraft, but Pentagon spokesman George Little has said that an American drone is missing and had not been recovered as of Thursday.
But two U.S. officials confirmed to CNN on Tuesday that the missing drone was part of a CIA reconnaissance mission that involved both the intelligence community and military personnel stationed in Afghanistan.
Iran's official Iran Republic News Agency said the country's armed forces had downed the drone near Kashmar, some 225 kilometers (140 miles) from the border with Afghanistan on December 4.
Salami said downing the plane was "very valuable for us" and "a victory for us and a defeat for our enemies," IRNA reported.
He also claimed Iran had downed other drones earlier but had not announced those instances because they were not as important.
Iranian TV aired images Thursday of what it says is the drone, an apparently intact RQ-170 drone propped on a pedestal and triumphantly displayed.
There was disagreement among Pentagon officials about whether the drone in the video was real. Military and intelligence officials were analyzing the Iran television footage.
One U.S. official said the United States can't be certain it's the real stealth drone, because U.S. personnel don't have access to it. But he added there's no reason to think it's a fake.
However, a second senior U.S. military official said that a big question is to how the drone could have remained virtually intact given the high altitude it is believed to have crashed from.
The condition of the drone in the video suggests it was not shot down but suffered a system failure, aviation analyst Bill Sweetman said. There are no burn marks from a fire, no holes and no outward damage. Sweetman noticed a dent along the leading edge but doesn't know what that means.
"It's fairly clear here from the pictures that the outer wings have been separated. The question is, did that happen in the accident or (did they take) them off to move the aircraft?" Sweetman asked.
The CIA and the Pentagon would not comment on the video shown Thursday.
A senior U.S. official with direct access to the assessment about what happened to the unmanned aircraft said it was tasked to fly over western Afghanistan and look for insurgent activity, with no directive either to fly into Iran or spy on Iran from Afghan airspace.
A U.S. satellite quickly pinpointed the downed drone, which apparently sustained significant damage, the senior official said.
Iran's U.N. ambassador said in a letter Thursday that the drone flew 250 kilometers (150 miles) into Iranian territory "to the northern region of the city of Tabas."
The letter from Ambasador Mohammad Khazaee to U.N. Secretary-Genera Ban Ki-moon and the heads of the General Assembly and Security Council said the drone "faced prompt and forceful action" by the armed forces.
"My government emphasizes that this blatant and unprovoked air violation by the United States government is tantamount to an act of hostility against the Islamic Republic of Iran in clear contravention of international law, in particular, the basic tenets of the United Nations Charter," Khazaee's letter said.
He called for U.N. condemnation of U.S. "acts of aggression," as well as "clear and effective measures to be taken to put an end to these dangerous and unlawful acts in line with the United Nations' responsibilities to maintain international and regional peace and security."
Journalist Shirzad Bozorgmehr and CNN Pentagon Correspondent Chris Lawrence contributed to this report.