North Korea's state media said leader Kim Jong-un on Monday guided a tactical drill simulating a nuclear counterattack involving super-large multiple rocket launchers against enemy targets, Yonhap news agency reported.

"If North Korea attempts to use weapons, it will face an immediate, overwhelming and decisive response from the South Korea-US alliance, and the North Korean regime will face its end," ministry spokesperson Jeon Ha-kyu said in a regular press briefing.

Jeon said North Korea's continued provocations would only strengthen South Korea's military capabilities and US extended deterrence, and their trilateral security cooperation involving Japan.

Extended deterrence refers to America's commitment to using the full range of its military capabilities, including nuclear, to defend its ally. The allies have been pursuing an integrated form of extended deterrence with Seoul leveraging its high-tech conventional military capabilities.

The Joint Chiefs of Staff (JCS) said the North's latest missile tests appear to be "a show of force" against the ongoing military drills between Seoul and Washington as well as demonstrating its capabilities in lieu of its delayed spy satellite launch and arms sales abroad.

The South Korean military said earlier North Korea appears to be making preparations for its next launch of a spy satellite, although there are no signs of an imminent launch.

JCS spokesperson Lee Sung-jun evaluated North Korea's claim of a nuclear attack capability as "exaggerated" and the South Korean military is ready to detect and shoot down its ballistic missiles.

"North Korea is known to have not yet concluded its experiments with small tactical nuclear weapons," Lee said during the briefing.

The North's super-large multiple rocket launch system is classified as a short-range missile that could put the entire South Korean territory within range. Pyongyang has claimed a tactical nuclear warhead could be mounted on such a weapon.

The North said Monday's missiles accurately hit the target island within a 352-kilometer range, which is enough to hit South Korea's Gyeryongdae military headquarters, 160 kilometers south of Seoul, and an air base in Gunsan on the southwestern coast, where the joint aerial drills have been underway.

On Tuesday, JCS Chairman Adm. Kim Myung-soo visited the 707th Special Mission Group, an elite counter-terrorism unit under the Special Warfare Command, to review its military readiness.

Kim highlighted the special force's role in eliminating the enemy's leadership in covert operations during a conflict and called for heightened vigilance against North Korean threats.