The chief US nuclear negotiator was in Beijing Wednesday to confer with Chinese counterparts on how to restart international disarmament talks with North Korea amid concerns the regime might soon test a nuclear bomb. The envoy, US Assistant Secretary of State Christopher Hill, expressed frustration over North Korea's refusal to return to the six-nation talks on its nuclear ambitions, after arriving Tuesday in Beijing. "The problem right now is that the ... North Koreans apparently have no interest right now in joining the diplomatic process," Hill said. "We regard this as not only too bad for the process but too bad, too, for them." He was to hold talks Wednesday with his Chinese counterpart Wu Dawei, China's point-man in the six-nation nuclear talks. He also met Vice Foreign Minister Cui Tiankai, the country's chief envoy in charge of nonproliferation issues. Hill said the United States wanted to consult with the Chinese about the possibility of a North Korean nuclear test or a repeat of the North's missile launches in July. "How can we prevent them from happening and if they happen anyway, what will we then do about that. That's something we do want to be in close contact with the Chinese about," Hill said on Tuesday. The two agreed to cooperate with China, Russia and South Korea to bring the North back to the talks, which are aimed at persuading the reclusive regime to give up its nuclear ambitions. Pyongyang has boycotted the negotiations until Washington lifts financial restrictions aimed at the North.