The US and the South Korean military personnel have kick-started their annual joint military exercise at Yongsan Garrison, Seoul, South Korea.
Code-named Ulchi Freedom Guardian 2015 (UFG 2015), the exercise involves participation from approximately 80,000 South Korean and US soldiers, and aims to protect Seoul against an attack by a North Korea, Yonhap News Agency reported.
UFG 2015 will also feature forces from seven UN Command Sending States, including Australia, Canada, Colombia, Denmark, France, New Zealand, and the UK.
In addition, the Neutral Nations Supervisory Commission will monitor the exercise to ensure it is in compliance with the Armistice Agreement.
Initiated in 1976, the UFG is a routine and defence-oriented exercise designed to augment readiness of the Republic of Korea-United States Combined Forces Command (CFC), and protect the region and maintain stability on the Korean peninsula.
North Korea has threatened to retaliate against the exercise, which is said to be the world's largest computerised command and control drill and concludes on 28 August.
A statement by the Committee for the Peaceful Reunification of Korea, carried by the Korean Central News Agency, said: "The DPRK is fully ready to counter any war method of the US imperialists and has a muscle powerful enough to deter a nuclear war to be provoked by the US."
North Korea routinely calls the joint military exercise 'a declaration of war,' despite the CFC's insistence that the training is non-provocative in nature. The country is also expected to test-launch missiles during the drill period.
In response, South Korean military chief Admiral Choi Yoon-hee said: "The (South Korean) military is standing with a war-readiness position, under which any types of North Korean provocations could be retaliated against strongly at the spot."