Iran's Revolutionary Guards said the drone was "shot down by air defense fire of the Revolutionary Guard's Revolutionary Force" in Iran's southern province of Harshzakan, state television reported.
The plane, a Global Hawk (manufactured by US company Northrop Grunman), was shot down in Kowa Mubarak district of Kharzakan province after "penetrating the Islamic Republic of Iran," the television and the agency said.
In turn, the US military confirmed the fall of a US military drone with an Iranian missile in international waters over the Straits of Hormuz.
The incident comes amid tension between Iran and the United States. The US military on Wednesday accused Iran of responsibility for an attack on a Japanese tanker in the Sea of Oman on June 13.