The leaders of Russia and Japan have expressed "disappointment and profound concern" at North Korea's decision to withdraw from the Nuclear Non-Proliferation Treaty (NPT).

The North Korean crisis has overshadowed the countries' meeting

In a joint statement released following talks in Moscow, Russian President Vladimir Putin and Japanese Prime Minister Junichiro Koizumi also called on all sides to find a peaceful solution to the standoff.

"[Russia and Japan] support a peaceful resolution of all questions linked to North Korea's nuclear program, in the interest of supporting non-proliferation and securing the Korean Peninsula's non-nuclear status," the leaders said.

However at a later news conference Mr Putin said that both countries had studied North Korea's statement announcing its withdrawal from the NPT and found that the country's leadership "is keeping the door open for talks"; expressing hope that the escalating crisis could be resolved.

"We expect that during such talks, all questions and concerns of both parties can and will be solved," Mr Putin said.

Russian 'influence'

Mr Koizumi's first visit to Russia as prime minister - and his fourth meeting with the Russian president - has been overshadowed by the growing crisis over North Korea's nuclear weapons ambitions.

Earlier the Japanese leader had said that Japan must co-operate closely with Russia as it has rare diplomatic relations with North Korea.

"I think Russia holds strong influence over North Korea, and I also think Russia has a perspective on North Korea that Japan does not have," he said.

Mr Putin has met North Korea's reclusive leader Kim Jong-il three times, but analysts believe Russia has not been informed of North Korea's intentions and therefore is likely to have little influence.

Mr Koizumi met Mr Kim in Pyongyang last September but talks on normalising relations with North Korea have stalled.

Mr Koizumi is to stop over in the Russian Far East city of Khabarovsk on his way back from Moscow, before returning to Tokyo on Sunday.

Island dispute

Relations between Russia and Japan are improving but remain cautious, largely because of a territorial dispute regarding four small islands seized by Soviet troops in the final days of World War II.

The islands, which lie off Japan's northern Hokkaido island, are known in Russia as the Kurils and referred to in Japan as the Northern Territories.

Following Friday's talks both leaders expressed their determination to resolve the dispute, saying they would "energetically pursue a mutually acceptable solution to the problem of signing a peace treaty", the Russian news agency Interfax reported.

The islands are surrounded by rich fishing grounds, and controlling the islands gives Russia access to the Pacific Ocean.

Trade between Russia and Japan has increased in recent years, and the two countries have been in talks over the joint construction of an oil pipeline in eastern Siberia.

Tokyo and Moscow set up diplomatic relations in 1956, but still have no formal peace treaty to end World War II.