Chinese and US diplomats met Wednesday amid efforts to restart nuclear disarmament talks with North Korea after Washington and Seoul threw out a possible complication by saying they would refuse to treat the North as a nuclear state. "Together, we have the responsibilities of world peace and global security," said US Undersecretary of State Nicholas Burns, who led the American delegation. The Chinese side was led by Yang Jiechi, a deputy foreign minister. Burns and Robert Joseph, a US undersecretary of state for arms control, were in Seoul on Tuesday and earlier visited Tokyo to coordinate strategy for renewed nuclear talks. Burns was scheduled to meet later with Chinese Foreign Minister Li Zhaoxing. North Korea agreed last week to end a yearlong boycott of Chinese-organized disarmament talks that also include the United States, South Korea, Japan and Russia. No date has been set.