U.S. Secretary of State Hillary Clinton has stressed that the U.S. and China must work together in rebuking North Korea for its attack on the Cheonan naval vessel.

Clinton on Sunday made the remarks in the opening session of the two-day Strategic and Economic Dialogue in Beijing.

Clinton said that the North must take the responsibility for the sinking as a joint military-civilian investigation revealed that the Cheonan sank due to the North's torpedo attack.

She also described the situation as "a matter of urgent concern," stressing Washington and Beijing must work together to address the challenge and promote peace and stability on the Korean Peninsula.