North Korea is refusing to proceed further with its nuclear disarmament unless other countries at arms talks guarantee their promised energy aid, a South Korean official said Thursday. Seeking to break the latest stalemate at the nuclear negotiations, the five other countries in the arms talks - the US, China, Japan, Russia and South Korea - met with the North on Wednesday in the truce village of Panmunjom in the middle of the Demilitarized Zone dividing the Koreas. "The North has taken the position that if that (energy aid) is not fully guaranteed, it cannot cooperate in making further steps" at the nuclear talks, South Korean negotiator Hwang Joon-kook said. "The North Korean side is now putting considerable importance on the energy and economic aid," he said. Following earlier agreements at six-nation arms talks, the North last year began disabling its main nuclear facilities so they cannot be easily restarted to produce material for bombs. The process has slowed due to disputes over the communist nation's failure to provide a declaration of its nuclear programs as it promised to do. North Korea complains it has completed 80 percent of the disablement but has only received about 40 percent of the promised energy aid worth 1 million tons of oil.