China and Russia are calling on North Korea and the United States to adhere to an agreement that required Pyongyang to give up its nuclear weapons program. The presidents of Russia and China urged Washington and Pyongyang to improve their relations.
Russian President Vladimir Putin and China's Jiang Zemin called for the Korean peninsula to be free of nuclear weapons.
In their joint statement Monday, the two leaders urged North Korea and the United States to work to improve their relationship. It was not clear if that meant establishing full diplomatic relations.
Tensions between Washington and Pyongyang have risen since October, when North Korea disclosed it is trying to develop nuclear weapons. China and Russia both border North Korea and supported that nation during its war with South Korea in the 1950's. The United States backed South Korea.
Mr. Putin and Mr. Jiang urged Washington and Pyongyang to abide by the 1994 Agreed Framework. Under that accord, North Korea promised to abandon efforts to build nuclear weapons in return for foreign energy aid. Monday's statement also urged North Korea to improve ties with South Korea and Japan.
Monday's meeting with President Jiang comes at the start of Mr. Putin's two-day visit, which is designed to improve ties between Moscow and Beijing.
Mr. Putin said the relationship between Moscow and Beijing has reached a "very high level" and that he hopes cooperation will continue. Mr. Putin said that when Russia and China cooperate on terrorism the world is more stable.
In Monday's statement, the two presidents supported each other's efforts to fight Muslim separatists within their borders. Both nations face a threat from separatist rebels - Russia from Chechen rebels and China from independence-minded Muslims in its western Xinjiang region.
During his visit, Mr. Putin also is expected to discuss Iraq's weapons program. Both Beijing and Moscow have urged using diplomatic means to get Baghdad to abandon efforts to build weapons of mass destruction. The United States accuses Iraq of violating the terms of its 1991 surrender in the Gulf War by attempting to make such weapons.
President Putin arrived before dawn Monday morning. He is expected to meet with Mr. Jiang's successor, Chinese Communist Party Chief Hu Jintao, and will speak at Peking University before leaving on Tuesday.