Iran’s defense minister, responding to Pentagon claims that Iran shot at a U.S. military drone this month, acknowledged late Friday afternoon that the incident had taken place.

“Last week an unknown airplane entered the airspace over Iranian waters of the Persian Gulf,” Ahmad Vahidi said in remarks quoted by the semi-official Fars and Mehr news agencies. “At the correct moment, Iran was vigilant and took firm action, which forced the plane to escape.”

The Pentagon said Thursday that an Iranian warplane had opened fire Nov. 1 on an unarmed MQ-1 Predator drone conducting surveillance in the first such incident over the gulf. The plane returned to its base unscathed, U.S. officials said.

Although the United States claims that the drone was shot at over international waters, Iran contends that its maritime border extends past Abu Musa, an island about 45 miles from the Iranian coastline whose ownership has been the focus of a decades-long dispute with the United Arab Emirates.

Vahidi went on to praise Iran’s preparedness, as well as the action it took, saying, “This experience, and previous background, shows that the Islamic Republic of Iran, with the required wisdom, monitors all movements precisely and will carry out authoritative, firm, required and timely action.”

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“The Islamic Republic, with the use of all resources, will follow up this case in the appropriate international bodies,” he added.

The United States relies heavily on drones to spy on nations where it has limited human intelligence assets. In Iran, the stealth aircraft have been deployed to assess the country’s nuclear program.