South Korea and the United States kicked off their annual joint military exercises on Monday, after the Democratic People's Republic of Korea (DPRK)'s supreme military command announced it would scrap the Korean War Armistice Agreement, in response to the drill, which is scheduled to run through March 21.

The "Key Resolve" military exercise will be held for almost two weeks starting Monday, bringing together 10,000 South Korean troops and 3,500 U.S. troops, according to the defense ministry here.

According to Yonhap News Agency, such practice is needed as Seoul prepares to regain its wartime operational control (OPCON) from Washington at the end of 2015.

Tensions have escalated sharply on the Korean Peninsula as DPRK has vowed to nullify an armistice that halted the 1950-53 Korean War from March 11, and warned of more and stronger counter- measures if the United States and South Korea continued joint military drills.

DPRK also cut off a communication hotline with South Korea on Monday, Yonhap said.