TAIPEI (Taiwan News) — Communist China lodged "stern representations" on Tuesday (Aug. 25) after a U.S. U-2 reconnaissance aircraft flew over a no-fly zone set up over People's Liberation Army (PLA) live-fire drills.

In a statement released on Tuesday, China’s defense ministry complained that a Lockheed U-2 high altitude reconnaissance aircraft flew over a northern military region during a live-fire exercise that day, "seriously interfering in normal exercise activities." The ministry claimed that the U-2's presence could cause a misunderstanding or misjudgment or an “unexpected incident.”

The ministry condemned the flight as "an act of naked provocation" and said that it lodged "stern representations" to the U.S. over the matter. It then called on the U.S. to put an immediate halt to such "provocative behavior" and take concrete steps to maintain peace and stability in the region.

The U.S. responded with its own statement that day in which it wrote that the mission had taken place over the Indo-Pacific region and that it was “within the accepted international rules and regulations governing aircraft flights.”

Neither side specified where the flight took place, and China is currently carrying out military exercises in the Bohai Sea, Yellow Sea, and the South China Sea.

Nicknamed the "Dragon Lady," the U-2 is a single-seater single-engine high-altitude reconnaissance aircraft of the U.S. Air Force. It can perform all-weather reconnaissance missions at a top speed of 805 kilometers per hour, an altitude of up to 21,336 meters, and a range of 960 kilometers.