A team of U.S. nuclear experts is expected in North Korea to survey the country's Yongbyon nuclear complex and help plan its disablement.
U.S. State Department Spokesman Sean McCormack told reporters that the team was set to leave the U.S. Tuesday.
U.S. President George Bush spoke by phone Tuesday with South Korean President Roh Moo-hyun about last week's inter-Korean summit and the denuclearization of the North Korean peninsula.
In July, North Korea shut down its main nuclear plant and last week, it pledged to disclose all of its facilities and disable them by the end of the year.
North Korea marked the anniversary of its first nuclear test Tuesday, calling it a "great miracle" for all Koreans.
A commentary in the North's main "Rodung Sinmun" daily did not mention how the test increased the isolation of the country or triggered painful sanctions.
Instead, the article said the nuclear test helped make North Korea a "powerful and great nation" during a time of hardship.
Shortly after the 2006 nuclear test, North Korea returned to six-party talks aimed at ending its nuclear ambitions, and in February of this year agreed to begin the process of dismantling its nuclear facilities.
Some information for this report was provided by AP.