Story highlights North Korea's ambassador to U.N. says U.S.-South Korean military drills are a "beheading operation"

Ambassador JA Song Nam says drills threaten international peace and security

(CNN) The North Korean ambassador to the U.N. has filed a request for the body's Security Council to meet over the ongoing U.S.-South Korean joint military exercises.

The letter, obtained by CNN, calls the "Key Resolve" and "Foal Eagle 16" joint military operations, the largest to date , "aggressive" and directed toward the DPRK, an acronym for North Korea used by the regime.

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The letter, written by North Korea's Permanent Representative, Ambassador, JA Song Nam, and addressed to the the president of the Security Council, Ismael Abraao Gaspar Martins, alleges that the operations are a "beheading operation" aimed to remove the supreme leadership of the DPRK and "bring down its social system."

Previous attempts by North Korea to convene the Security Council have failed.

Earlier this month the regime threatened a preemptive nuclear strike over the war games, which are held annually but have this year been ramped up to include 300,000 South Korean troops and at least 17,000 U.S. forces.