Seoul - North Korea on Wednesday threatened to shoot down US spy planes flying entering its airspace ahead of a planned satellite launch.

The state-run Korean Central Broadcasting Station accused the United States and South Korea in a radio broadcast of violation of North Korean airspace.

At least 190 reconnaissance flights had occurred in March alone, including flights over the Musudan-ri launch site on North Korea's east coast, the South Korean Yonhap news agency quoted the station as saying.

"Should the US imperialist racketeers dare to perpetrate aerial espionage, interfering with our preparations for a satellite launch for peaceful purposes, our revolutionary forces will shoot them down without spare," the radio station said.

Pyongyang already on Tuesday accused Washington having sent in a RC-135 spy plane to take pictures of Musudan-ri, as the announced launch window of April 4-8 draws near.

North Korea announced it would launch a communications satellite, but the US as well as neighbours South Korea and Japan suspect it is a cover for the test of the Stalinist state's long-rage Taepodong-2 missiles, leading to increased tension in the region.

Seoul and Washington said they wanted to discuss Pyongyang's plans at the United Nations Security Council, as they regard the planned launch a violation of a Security Council resolution banning North Korea from conducting missile tests. (dpa)