Iran has claimed its engineers have successfully created a copy of a US drone captured in 2011.
Iran's state television broadcasted footage of what they said was the replica of a US RQ-170 Sentinel drone made by Lockheed Martin.
"Our engineers succeeded in breaking the drone's secrets and copying them," an officer on the footage reportedly said. "It will soon take a test flight."
The drone was unveiled at an exhibition organised by Iran's Revolutionary Guards attended by the Supreme Leader, Ayatollah Ali Khamenei.
Photos of the event were published on Khamenei's official website.
AFP news agency quoted Khamenei as saying that the drone was "very important for reconnaissance missions".
Iran said they captured the drone as it was flying through the country's airspace, possibly monitoring military and nuclear facilities in 2011.
Washington later confirmed they had lost an aircraft but US officials claimed that Iranians would have struggled to decipher the drone's secrets as they lacked the necessary technology.
In December 2011 US president Obama demanded Tehran give back the drone but the request was turned down.
"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," Gen. Hossein Salami, deputy commander of Iran's military, said.
Last year Iran's claims that it had successfully test-flown a domestically produced fighter jet was ridiculed by aviation expert who said released photos of the aircraft soaring over Iranian mountains were doctored.