South Korea and the United States will begin a major combined military exercise next week to strengthen their joint defense readiness in the face of evolving North Korean military threats, the Joint Chiefs of Staff said Monday.

The annual Ulchi Freedom Shield exercise is set to take place from Aug. 19-29, featuring the main computer simulation-based command post exercise, concurrent field training and civil defense drills.

The move comes amid heightened cross-border tensions due to Pyongyang's launches of thousands of trash-loaded balloons toward South Korea since late May in a tit-for-tat move against anti-Pyongyang leaflets flown by activists in the South.

The JCS said this year's exercise will reflect threats across all domains, including those posed by North Korean missiles, GPS jamming, cyberattacks as well as lessons learned from recent armed conflicts.

"In particular, the ROK-US alliance will further strengthen its capability and posture to deter and defend against weapons of mass destruction," it said in a release. ROK stands for the Republic of Korea, the South's official name.

Aside from South Korean and US troops, personnel from several member countries of the UN Command will join the exercise. The UNC is an enforcer of the armistice that halted the fighting in the 1950-53 Korean War.

The North has long denounced the allies' joint exercises as a rehearsal for an invasion against it and has a track record of staging weapons tests in response. South Korea and the United States have rejected the accusation, describing their drills as defensive in nature. (Yonhap)