North Korea accused the United States on Wednesday of conducting about 170 spy flights against the communist country in May.
The U.S. spied on strategic targets, coasts and sea floors around North Korea from skies over the South, using such planes as the U-2, RC-12 and EP-3, the North's official Korean Central News Agency reported, citing unidentified military sources.
The report said more than five reconnaissance flights had taken place daily.
North Korea publishes its claimed tally of alleged U.S. aerial espionage every month. The U.S. military never comments, although it acknowledges monitoring North Korean military activity.
Some 29,500 U.S. troops are stationed in South Korea, which remains technically at war with the North as the 1950-53 Korean War ended in a cease-fire, not a peace treaty.