The US and Japanese nuclear envoys headed to Beijing on Sunday ahead of international talks on dismantling North Korea's nuclear weapons program in return for security guarantees and aid. Chief US envoy Christopher Hill was set to meet his North Korean counterpart Kim Kye Gwan in the Chinese capital, a day before the six-country talks start Monday. "I hope they come ready to make some progress, because we need progress," Hill told reporters in Tokyo early Sunday, before he left for Beijing. "The issue is implementing the September (2005) statement," Hill said, referring to the North's agreement to abandon its nuclear weapons program in exchange for security guarantees and aid. "The question is what part of the September statement are they prepared to move on?"