George W. Bush telephoned Vladimir Putin following Pyongyang's announcement that it had successfully detonated a nuclear device underground.
The announcement triggered a chorus of condemnation from world leaders, with some calling for UN Security Council sanctions against the reclusive communist regime.
The Kremlin press office said Vladimir Putin and George W. Bush "share a view that North Korea's ostentatious action undermines the non-proliferation regime, and stress the need for coordinated action to resolve the issue."
Earlier on Monday, Putin said: "Russia absolutely condemns the test in North Korea, which has inflicted great damage on the non-proliferation process." He also urged Pyongyang to return to disarmament talks.
Moscow, Washington, Beijing, Tokyo and Seoul have been trying to persuade Pyongyang to abandon its nuclear program in exchange for aid and security guarantees since it withdrew from the Nuclear Non-Proliferation Treaty in 2003. But the intermittent six-party talks have repeatedly stalled.
Russia, which shares a small border with North Korea, was the first country to confirm the test. Defense Minister and Deputy Prime Minister Sergei Ivanov said the power of the detonation was equivalent to 5,000-15,000 tons of TNT, contradicting U.S. estimates that the explosion had been much smaller.
Russia's Foreign Ministry issued a statement saying: "This step, made in defiance of all appeals from the international community, threatens a further escalation of tensions on the Korean peninsula, undermines the nuclear non-proliferation regime, and sets a precedent for a nuclear arms race in Northeast Asia."
