South Korea and the United States launched Tuesday an annual joint military exercise aimed at enhancing their interoperability in defense.

South Korea and the United States launched Tuesday an annual joint military exercise aimed at enhancing their interoperability in defense.

The 10-day computer-assisted command post exercise, dubbed Ulchi Freedom Guardian, will be joined by 530,000 troops from South Korea, the U.S. and seven "United Nations Command" sending nations. The drill is to take place on the Korean peninsula and at U.S. military headquarters in the Pacific and the U.S., according to the Combined Forces Command (CFC) here.

The U.S.-led "United Nations Command" has informed the Democratic People's Republic of Korea (DPRK) of the defensive nature of the routine drill, according to the CFC.

The drill is "focused on preparing, preventing and prevailing against the full range of current and future external threats" to South Korea and the region, Gen. James D. Thurman, Combined Forces Command Commander, said.

"We are applying lessons learned out of Iraq and Afghanistan, as well as those garnered by the alliance's recent experiences with North Korean (DPRK) provocations on the peninsula and past exercises," he added.

The DPRK demanded last week the allies cancel the joint exercise, which it sees as a plot against Pyongyang.