U.S. Ambassador to South Korea Philip Goldberg on Thursday called on China and Russia to do more to convince North Korea to denuclearize, reiterating Washington’s recent messages that the two permanent U.N. Security Council (UNSC) members must live up to their commitments on sanctions.

“China, as well as the United States and Russia, all passed resolutions at the U.N. on the missile and nuclear developments in North Korea,” he said at a press briefing organized by the Seoul Foreign Correspondents’ Club (SFCC). “We all ought to follow that rules-based solution to getting to negotiations and to denuclearization.”