North Korea on Thursday dismissed South Korean President Lee Myung-bak‘s recent New Year speech as nothing but “sophism,” saying that it will strengthen its nuclear power status if its “enemy” continues its provocative action.

This strong word is the first official response by the North to President Lee’s speech on Monday, in which he said that South Korea has left a “window of opportunity” open to improve relations with North Korea.

But Lee repeated his previous stance that the six-party talks on ending North Korea‘s nuclear weapons programs can resume only if Pyongyang halts all of its nuclear activities.

“’Sincerity‘ and ’peace and stability‘ touted by Lee is also no more than sophism intended to evade the blame for bringing the inter-Korean relations to a collapse,” the North’s Secretariat of the Committee for the Peaceful Reunification of Korea said in an “information bulletin” carried by Pyongyang‘s Korean Central News Agency.

“As recognized by the world, the DPRK is a full-fledged nuclear weapons state ... As long as the enemy is persistent in his moves for aggression, the DPRK will further reinforce the position of the nuclear weapons state to protect its dignity and sovereignty,” it said.

The DPRK is the acronym of the North’s official name, the Democratic People‘s Republic of Korea.

The committee added that the Lee government would be “mistaken”

if it thinks that “it can have a bargaining over this precious revolutionary heritage with the promise of any aid, referring to its nuclear weapons.

The harsh comments came as South Korea’s Unification Minister Yu Woo-ik said earlier on Thursday that Seoul keeps its door open for dialogue with North Korea, adding that it could have working-level inter-Korean talks.

Inter-Korean ties are currently at one of their lowest levels in years. In a series of hostilities against South Korea in 2010, North Korea sank a South Korean warship and attacked a border island with artillery fire, killing a total of 50 South Koreans. (Yonhap News)