By ELIANE ENGELER – 5 hours ago GENEVA (AP) ― The top U.S. nuclear negotiator on North Korea said the two sides made progress in their stalled nuclear talks on Thursday but were still short of an agreement. Assistant U.S. Secretary of State Christopher Hill told reporters that the talks in Geneva were probably the most substantive that Washington has had with North Korea since problems developed in December over disarming Pyongyang's nuclear weapons program. "We certainly are further along in this consultation than we were when I arrived this morning," Hill said. "There has been progress." "We're going to report to capitals and see where we are tomorrow and the next day," Hill said after meetings with North Korean Vice Foreign Minister Kim Kye Gwan. THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below. GENEVA (AP) ― North Korea must include everything about its nuclear weapons program in a promised declaration, Washington's top nuclear negotiator said Thursday as he sat down for talks with officials from Pyongyang. Assistant Secretary of State Chistopher Hill said he's willing to be flexible on the format ― but "the declaration has to be a complete and correct declaration." He was meeting Thursday with North Korean Vice Foreign Minister Kim Kye Gwan at Pyongyang's request to see if they can make a breakthrough in stalled diplomatic talks over North Korea's nuclear weapons program. Kim did not speak to reporters before the meeting at the U.S. Mission to United Nations offices in Geneva. The United States says North Korea has come up short on its agreement to declare details about its nuclear weapons program. "We need to get some movement. We're already some 10 weeks behind," Hill said, referring to the North Korean commitment to make a full declaration of the program by the end of 2007. Pyongyang says the aid it is to receive in exchange is late. "We have some ideas that may be workable, but they're only workable within the context of providing a complete and correct declaration," Hill said in Washington before his departure. "We cannot have a situation where they don't give us a complete declaration and where we try to ignore elements that need to be there." Any list, he said, must include details about an alleged secret uranium nuclear program. Hill indicated a willingness to give North Korea some leeway on how to present its declaration. "What the pieces of paper look like: I think we should be a little flexible on the format, but with the understanding that flexibility on format doesn't mean flexibility on getting a complete and correct declaration," he said. In a previous meeting in Geneva last September, Hill and Kim cleared the way for unprecedented progress in the disarmament process, with North Korea agreeing to declare details about its nuclear weapons program by the end of the year. Pyongyang shut down and started to disable its main nuclear reactor. But then progress stalled, with North Korea complaining that promised energy aid was late in coming. Washington said Pyongyang still had to provide a detailed declaration of its nuclear programs as a condition for receiving the assistance, and North Korea insisted it gave the U.S. a list of its nuclear programs in November. Since then, six parties ― the U.S., the two Koreas, China, Japan and Russia ― have been trying to resolve the dispute. This week's talks could mean North Korea is ready to respond to a proposed compromise China reportedly has crafted as host of the ongoing six-nation negotiations on the North's nuclear disarmament. South Korea's Yonhap news agency, citing "diplomatic sources" in Washington, said the proposed compromise calls for Washington and Pyongyang to issue a joint statement explaining their positions on key points. "I expect a quick resolution of the declaration issue," South Korean Foreign Minister Yu Myung-hwan told reporters. The main issues are believed to be whether North Korea had a clandestine uranium-based nuclear program and whether it has shared its nuclear technology with others. Pyongyang strongly denies both allegations. Associated Press writers Foster Klug in Washington, Kwang-tae Kim in Seoul, South Korea, and Eliane Engeler and Frank Jordans in Geneva contributed to this report.