North Korea on Saturday denounced an upcoming South Korea-U.S. military exercise, calling it preparations for a nuclear war against it.

South Korea and the United States are scheduled to stage the Ulji Freedom Guardian exercise from Aug. 20 through Aug. 31. North Korea typically denounce it and other joint military drills staged by the allies annually as war preparations.

"Such projected saber-rattling is a reckless move as it openly reveals the scenario of the U.S. and south Korea to seize the DPRK by force of arms, and an extremely dangerous attempt to ignite a fresh war on the Korean Peninsula at any cost," the Korea Central News Agency (KCNA) said in a commentary, monitored in Seoul.

The computer-aided exercises will mobilize some 56,000 South Korean troops and about 30,000 U.S. soldiers, including some 3,000 from the mainland U.S. and other bases around the Pacific region.

The troops from seven United Nations Command states -- Australia, Britain, Canada, New Zealand, Denmark, Norway and France -- will participate in the drill as observers.

Tension on the Korean Peninsula remains high following the North's two military attacks in 2010 that killed 50 South Koreans.

The South's military has vowed tougher retaliations if provoked again.

The Koreas remain technically at war because the 1950-53 Korean War ended in an armistice. About 28,500 U.S. soldiers are stationed in South Korea as a legacy of the war. (Yonhap News)