SEOUL - The Republic of Korea's ruling party asked the military authorities on Monday to review special countermeasures including the deployment of a nuclear-powered submarine to fundamentally contain submarine-launched ballistic missiles of the Democratic People's Republic of Korea (DPRK).

Rep. Chung Jin-suk, Saenuri Party floor leader, said at a party meeting that the DPRK's SLBM launch is a severe threat to security in the ROK and Northeast Asia as it is harder to detect where SLBMs are fired than ground-based missiles.

His comments came after the DPRK test-fired a ballistic missile from a submarine off its east coast on Aug 24. Seoul's military said the missile flew about 500 km toward Japan, surpassing the flight distance of 300 km which the ROK's defense ministry regards as a success.

A completed SLBM technology would raise the DPRK's nuclear threat to a new level as it is very hard to detect and track a DPRK missile from a submarine moving secretly deep under the waters.

Chung said the military had pushed to build a 4,000-ton nuclear-powered submarine in 2003 under the Roh Moo-hyun government, asking the military to actively review the nuclear-powered submarine deployment along with the installation of a US missile shield in South Korea.

Seoul and Washington agreed in early July to deploy one Terminal High Altitude Area Defense (THAAD) battery in southeastern South Korea by the end of next year.

Facing strong oppositions from residents and politicians, Seoul's defense ministry said it would reconsider where the US missile defense battery is sited only within Seongju county, some 250 km southeast of capital Seoul.

Rep. Choo Mi-ae, newly elected chairwoman of the main opposition Minjoo Party, said on Saturday that she would push to make clear oppositions to the THAAD deployment by adopting the opposition as an official party view. Her comments were made after she was elected as the party head.