Russia and Japan are alarmed at North Korea's decision to withdraw from the Nuclear Non-Proliferation Treaty. Japanese Prime Minister Junichiro Koizumi and Russian President Vladimir Putin condemned the move at a summit meeting in the Kremlin.
The two leaders called on North Korea to reconsider its decision to abandon the treaty, which aims to control the spread of nuclear weapons.
At the end of their Kremlin meeting, the two men stressed that dialogue is the way to end the nuclear standoff.
North Korea's decision to withdraw from the treaty is the latest move in its dispute with the United States about its nuclear program, which it recently restarted.
The secretive communist regime says it took the move in self-defense, and it blames Washington for the impasse.
The United States says North Korea must honor the commitment it made in a 1994 agreement to shut down the nuclear program in exchange for fuel oil and civilian nuclear power technology.
Mr. Putin and Mr. Koizumi are in a unique position, as both men have met North Korean leader Kim Jong-Il in recent months.
Russia in particular is considered to have certain leverage, because it maintains good relations with North Korea.
During the Moscow summit, the two leaders also signed a joint statement aimed at strengthening economic relations between Japan and Russia.
The statement also calls for increased cooperation in the fight against terrorism.
The two men also reportedly discussed a long standing territorial dispute between Russia and Japan.
Tokyo has called for the return of four islands just north of Japan, which the Soviet Union seized at the end of World War II. The two nations have never signed a formal peace treaty because of the dispute, which has also blocked trade and foreign investment.