Seoul, Aug 29 (IANS): South Korea's ruling party on Monday asked military authorities to review special countermeasures including deployment of a nuclear-powered submarine to contain North Korea's submarine-launched ballistic missiles (SLBM).

Chung Jin-suk, Saenuri Party floor leader, said at a party meeting that North Korea's SLBM launch is a severe threat to security in South Korea and Northeast Asia as it is harder to detect where SLBMs are fired than ground-based missiles, Xinhua news agency reported.

His comments came after North Korea test-fired a ballistic missile from a submarine off its east coast on August 24.

Seoul's military said the missile flew about 500 km toward Japan, surpassing the flight distance of 300 km which South Korean defence ministry regards as a success.

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