As the North faced more condemnation over the incident, its main ally and chief benefactor China said restraint is needed to prevent escalation of tensions on the Korean Peninsula, Chinese spokesman Ma Zhaoxu said at the second round of the China-U.S. Strategic and Economic Dialogues in Beijing, the official Xinhua news agency reported.
Ma said Chinese and U.S. sides touched on many important issues, including the sinking of South Korea's Cheonan March 26 in the Yellow Sea.
Last week a team of international investigators found the ship was hit by a North Korean torpedo but the North has denied any role. Since the finding, North has come under increasing pressure from the South and its allies as also the United Nations.
The White House expressed support for Lee's measures and said President Barack Obama had directed U.S. military commanders to coordinate closely with their South Korean counterparts "to ensure readiness and to deter future aggression."
Ma said China has been highly concerned about latest developments.
"China has always been committed to maintaining the stability in Northeast Asia and the Korean Peninsula, promoting the six-party talks and denuclearization of the Peninsula," Ma said.
China issued a similar statement after the finding about North Korea's involvement was announced last week.
The ship incident will be brought before the U.N. Security Council. China, one of the council's five permanent members, can veto any resolution imposing more sanctions on the North.