President Bush says North Korea could face "tougher measures" if it does not agree to give up its nuclear weapons program.
While President Bush believes the crisis over North Korean nuclear weapons can be resolved peacefully, he said the United States and Japan will not be blackmailed by North Korean threats.
"We will not settle for anything less than the complete, verifiable and irreversible elimination of North Korea's nuclear weapons program," emphasized the president.
After meeting with the Japanese leader at his Texas ranch, Mr. Bush said the two countries are determined to confront the North Korean threat while continuing to pursue a peaceful solution.
"We are confident that our diplomatic approach will bring a peaceful solution," he said. "Yet we agreed that further escalation of the situation by North Korea will require tougher measures from the international community."
Both leaders thanked China for hosting face-to-face talks between U.S. and North Korean officials but said future meetings on the issue talks should also include South Korea and Japan.
Prime Minister Koizumi said North Korea's nuclear weapons program is a "grave challenge" to the entire world.
"We will not at all tolerate the possession, the development, or the transfer of nuclear weapons by North Korea," asserted the Japanese Prime Minister. "North Korea must promptly and completely dismantle all nuclear weapons development programs in a verifiable manner."
Prime Minister Koizumi said North Korea has to understand that its threats have what he calls, "no meaning whatsoever."
North Korea has withdrawn from the Nuclear Nonproliferation Treaty and is moving to restart nuclear facilities suspended as part of a 1994 agreement with Washington.
Pyongyang says its nuclear program is only meant to generate electricity. U.S. officials say it could produce enriched uranium for nuclear weapons.
North Korea and South Korea Friday ended four days of talks by agreeing to reopen railway links between the countries and begin building an industrial park in North Korea near the border.
The deal came after both sides clarified remarks that had earlier disrupted the talks in the North Korean capital. North Korea warned of what it called "unspeakable disaster" if South Korea joined the United States in opposing Pyongyang's nuclear program.
South Korea then threatened what it called "further steps" against the North if that program continues. Reports say the dispute was settled when both sides said their statements were not meant to threaten the other with military action.
South Korea and Japan both want President Bush to rule out the use of force against North Korea. Mr. Bush says he is keeping all of his options open but remains convinced that a peaceful resolution is possible.