Chinese president Hu Jintao has told his American counterpart that tensions on the Korean peninsula could get out of control if they're not properly handled.
President Hu Jintao has conveyed his concerns to United States president Barack Obama in a telephone call.
South Korea on Monday started live-fire naval exercises, 13 days after the North shelled a South Korean island close to a disputed maritime demarcation line.
The United States, Japan and South Korea pressed China and Russia to help defuse tensions on the Korean peninsula.
In Washington, US Secretary of State Hillary Clinton met the Japanese and South Korean foreign ministers, saying all three shared grave concerns over "provocative attacks from North Korea."
Japanese Foreign Minister Seiji Maehara, in comments echoed by South Korean Foreign Minister Kim Sung-hwan, said all three countries hoped for more cooperation from Beijing and Moscow, which have appeared less eager to get tough with Pyongyang.