The presidents of China and Russia called on North Korea today to abandon any program to develop nuclear weapons and urged the United States and Japan to reduce tensions on the Korean Peninsula by resuming talks with the isolated, unpredictable nation.

The appeal was consistent with previous statements by the Chinese president, Jiang Zemin, and his Russian counterpart, Vladimir Putin. But the formal, joint declaration, issued after a high-profile summit here between the two leaders, was a public rebuke of North Korea by its two closest allies and appeared to be an attempt to raise the diplomatic pressure on Pyongyang.

"The sides consider it important for the destiny of the world and security in Northeast Asia to preserve the non-nuclear status of the Korean peninsula and the regime of non-proliferation of weapons of mass destruction," the declaration said.

Jiang and Putin emphasized the "extreme importance" of new talks between the United States and North Korea and called for a return to a 1994 agreement in which Pyongyang promised not to develop nuclear weapons in exchange for energy aid from the West, including the construction of nuclear power plants.

North Korea stunned the world in October by declaring the pact dead and announcing that it had started developing nuclear weapons again. The United States immediately suspended talks, saying it was pointless to continue discussions with a nation that does not keep its word.

It is unclear what kind of influence China or Russia still has over North Korea, a Cold War-era communist ally. North Korean leader Kim Jong Il visited both nations in rare trips abroad in recent years, and China is a major supplier of fuel, food and other aid. But meeting with President Bush at his Texas ranch in October, Jiang said he was surprised by the North Korean nuclear weapons program and at a loss to explain Kim's intentions, according to Western diplomats.

Beijing's decision to arrest a Chinese businessman whom Kim had named to head a special economic zone also raised doubts about the closeness of the two nations' ties.