South Korea staged live-fire tank drills Thursday near the inter-Korean border, involving US military engineers, the Army said, as the allies' major annual springtime exercise came to a close.

The drills took place as part of a weeklong training at Seungjin Fire Training Field in Pocheon, just 25 kilometers south of the inter-Korean border, in connection with the combined Freedom Shield exercise designed to bolster deterrence against the North's nuclear and missile threats.

Some 300 personnel took part in the field training, which mobilized the Army's K1A2 tanks and K21 armored vehicles, among other assets, as well as M1150 assault breacher vehicles from a combined South Korea-US engineering unit.

South Korean and US troops formed joint battle teams in an effort to strengthen combined operational capabilities.

During the drills, K1A2 tanks and K21 armored vehicles fired at enemy targets as South Korean and US engineers removed obstacles to clear a path for troops to secure the enemy's position, according to the Army.

North Korea has long accused the allies' joint drills as rehearsals for an invasion against it, while Seoul and Washington have said they are defensive in nature.

On Wednesday, North Korean leader Kim Jong-un guided a training competition between tank units, where he drove a newly unveiled tank, state media reported, in an apparent show of force against the allies' drills.

The computer-simulated Freedom Shield exercise ended earlier in the day after kicking off March 4. The allies staged a series of concurrent on-field drills to boost readiness against North Korean threats.

The allies' navies have also been staging a three-day joint medical evacuation exercise since Thursday under a scenario of mass wartime casualties.

The drills mobilized a South Korean helicopter and two US choppers to transport injured personnel from Deokjeok Island off Incheon, west of Seoul, to the Armed Forces Daejeon Hospital in Daejeon, 139 km south of the capital, according to the South's Navy. (Yonhap)