Conservative contenders from the ruling Liberty Korea Party and the splinter Bareun Party said the killing of Kim Jong-nam in Malaysia on Monday underscores the need for South Korea to take a tougher line against the North, which they suspected is behind the attack.

Rep. Yoo Seong-min, a hopeful from the Bareun Party, said South Korea must deploy two or three Terminal High Altitude Area Defense

units of its own to better cope with North Korean provocations.

Liberal opposition parties oppose the deployment of the US missile shield, questioning its effectiveness and the negative impact it has on Seoul's relations with Beijing and Moscow.

Gyeonggi Gov. Nam Kyung-pil, from the same party, also urged South Korea to bolster its defense posture.

Former six-term lawmaker Rhee In-je, a potential contender from the Liberty Korea Party, said, "The assassination of Kim Jong-nam proves Pyongyang is gripped by anxiety. A power becomes most violent when it faces the end."

Rep. Won Yoo-chul of the ruling party repeated his argument that South Korea should seek its own nuclear armament.

Hopefuls from the opposition parties joined in on condemning North Korea and called for enhanced security measures, but refrained from jumping to the conclusion that Pyongyang was behind the attack.

"If it was a political assassination, it would be an unimaginable act of brutality," Moon Jae-in, former head of the main opposition Democratic Party said. "The government must promptly find out facts and objectively analyze its impact on national security."

"North Korea is not a normal country," Moon said. "We should always roll out inter-Korean policies considering that it is an unpredictable counterpart."

An Hee-jung, governor of South Chungcheong Province and affiliated with the opposition party, said, "We don't know whether the incident derived from the instability of the North Korean regime, or other issues, but it is shocking."

Seongnam Mayor Lee Jae-myung of the party also said the incident should work as an opportunity for people to pay more attention to the issue of human rights in North Korea. (Yonhap)