North Korea has warned that it would shoot down any U.S. reconnaissance planes that violate its airspace.

The North’s official Korean Central News Agency (KCNA) on Wednesday said that a U.S. RC-135 spy jet repeatedly flew along the North’s northeastern coast on March 22nd where the North is preparing to launch a rocket.

The KCNA claimed that the spy plane conducted aerial espionage and photographed North Korean strategic targets at the Musudan-ri launch site.

North Korea’s media regularly disclose its tally of monthly aerial spy flights by South Korea and the U.S., but it is rare for the North to issue such a warning.