President Yoon Suk Yeol called for an impenetrable security posture to maintain peace on the Korean Peninsula, as the government's annual civil defense exercise kicked off on Monday.

At a Cabinet meeting, Yoon said the four-day Ulchi exercise, involving more than 480-thousand people within the public sector, will help launch an overhaul of the nation's emergency response system in line with changing aspects of war.

The president warned against attempts to strike and incapacitate the country's war-fighting capacity and attacks on state information and communications networks, ports, airports and nuclear and semiconductor facilities.

Yoon also emphasized that the civil exercise should work in conjunction with Seoul and Washington's combined military training, the "Ulchi Freedom Shield," which also kicked off earlier in the day.