Congressional Democrats, demanding a bold new approach to end a diplomatic standoff, urged the Bush administration on Wednesday to dispatch the top US negotiator to North Korea to press for an end to its nuclear weapons program. The mission by Christopher Hill, which would begin first with talks with Chinese officials in Beijing, would demonstrate "our peaceful intent," Rep. Tom Lantos said as the House of Representatives International Relations Committee quizzed Undersecretary of State Nicholas Burns about the so-far futile effort to halt North Korea's nuclear weapons and missiles programs. Talks involving six nations are expected to resume next month after a suspension of more than a year. Burns said it was not possible yet to announce a precise date. While the United States has held sporadic, occasional talks with North Korea in New York and in Beijing, the administration insists on a six-nation negotiating format in an effort to intensify pressure on North Korea's insular communist-led government. "The North Korean problem is a regional problem," Burns said in defending the administration's approach. "It poses a threat to all of its neighbors."