President Bush is warning North Korea not to test-launch a long range missile. He spoke after talks at the White House with Japanese Prime Minister Junichiro Koizumi.
Both leaders made clear North Korea was high on the agenda for what is likely to be their last formal White House meeting.
President Bush told reporters there was complete agreement on the issue.
"We both agreed that it is very important for us to remain united in sending a clear message to the North Korean leader that, first of all, launching the missile is unacceptable," he said.
The president said North Korean leader Kim-Jong Il has provided no information on the long-range missile program and no clues as to his intent.
"There have been no briefings on what is on top of the missile. They have not told anybody where the missile is going. He has an obligation, it seems to me and the prime minister, that there be a full briefing to those of us who are concerned about it to see what his intentions are," he said.
Prime Minister Koizumi emphasized the importance of the six-party talks set up to deal with the North Korean nuclear issue. He said Japan and the United States must work in close coordination to encourage North Korea to "become a responsible member" of the international community.
The prime minister indicated that, during his two-hour meeting with Mr. Bush they discussed possible options, should North Korea ignore all the warnings and go ahead with a missile launch.
"Should they ever launch the missile, we would apply various pressures, and we discussed that. I believe it is best I do not discuss what specific pressures we were talking about," he said.
President Bush said, one way to deal with a North Korean launch would be through the United Nations. He also talked about enhanced efforts to develop and deploy anti-missile systems.
"The Japanese cannot afford to be held hostage to rockets," he said. "And neither can the United States or any other body who loves freedom."
Satellite images have suggested that North Korea may be preparing to test-fire a long-range ballistic missile, though there has been no confirmation from Pyongyang. The first time the North Koreans conducted a long-range missile test was in 1998 over Japan.