Two top US diplomats were set to meet with the Japanese foreign minister Monday after Japan and South Korea pledged to coordinate with Washington over resuming long-delayed talks on North Korea's nuclear program, officials said. South Korea's Foreign Minister Ban Ki-moon, who will be the next UN secretary-general, said that the three countries had worked closely together in the past, and would continue to do so at renewed six-nation disarmament talks expected later this year, according to a Japanese Foreign Ministry official. Ban was slated to meet Prime Minister Shinzo Abe on Monday. His trip coincided with visits to Tokyo by US undersecretaries of state Nicholas Burns and Robert Joseph. The two Americans were to meet with Aso and other Japanese officials on Monday before traveling to South Korea, according to Japan's Foreign Ministry.