Japan and South Korea have called for multilateral talks to seek a peaceful solution to North Korea's nuclear threat.
The two leaders spoke with one voice on North Korea
In a joint news conference after talks in Tokyo, South Korean President Roh Moo-hyun and Japanese Prime Minister Junichiro Koizumi said the issue was a threat not just to the Korean peninsula but to the peace and stability of East Asia.
They stressed the need to maintain "the momentum of dialogue" with North Korea which began in April, when US, North Korean and Chinese officials held talks in Beijing.
And they said they hoped that Japan and South Korea would be party to future group talks.
Correspondents say diplomats from Japan and South Korea have been sidelined as North Korea has insisted on dealing directly with the United States.
Both men welcomed China's mediating role in dialogue between Washington and Pyongyang.
On Friday, North Korea condemned United States plans to increase military spending on the Korean peninsula.
An official North Korean newspaper editorial described US plans to spend an extra $11bn to strengthen its forces in South Korea as "preparations for a pre-emptive attack" on the North.
"The US imperialists have already worked out a scenario for a
pre-emptive attack in a bid to implement their war strategy against
[North Korea]", the Minju Joson said.