President Bush says he expects North Korea to give up its nuclear weapons, and he warned Pyongyang not to be an arms proliferator.
Mr. Bush, speaking at the White House Thursday, refused to comment about U.S. intelligence reports that North Korea may have helped Syria with nuclear activities.
North Korea has denied the reports.
Earlier, a U.S. State Department spokesman said six-party talks on disabling North Korea's nuclear program may be rescheduled for next week.
The spokesman told reporters in Wednesday that host China has consulted with most of the parties about possibly meeting next week in Beijing. He said China still needs to discuss when to hold the talks with one country.
China has not commented on the remarks.
The envoys are to discuss the second phase of a nuclear disarmament agreement reached last February.
In the second phase, North Korea is required to declare all of its nuclear programs and disable its existing nuclear facilities. In return, it is to receive fuel and political concessions.
Some information for this report was provided by AFP and Reuters.