South Korean Foreign Ministry Spokesman Cho Hui-young told reporters Friday that Seoul welcomes President Bush's letter to North Korean leader Kim Jong Il. He says the letter shows President Bush's determination to support the process of North Korea's denuclearization.

North Korean broadcasters have been confirming Kim Jong Il's receipt of the letter, after first announcing it Thursday night. Prior to the North Korean announcement, U.S. officials and their regional partners made no mention of such a letter.

U.S. Assistant Secretary of State Christopher Hill delivered the letter last week in Pyongyang. Hill is Washington's representative at multinational talks to end North Korea's nuclear arsenal by diplomatic means.

He told reporters during a stop in Tokyo Friday North Korea is "quite on schedule" in disabling key nuclear facilities, as it promised South Korea, China, Russia, Japan and the United States it would do as part of a multi-stage agreement. He says the North will soon advance that process by removing spent fuel from its main reactor at Yongbyon.

However, Hill says more discussions are needed before North Korea fulfills another part of the agreement by producing a full declaration of all its nuclear facilities, materials, and existing weapons.

The United States has insisted the North account for an alleged uranium enrichment program Pyongyang has never publicly admitted. It also wants North Korea to address Washington's concerns about the possible transfer of nuclear equipment and technology to Syria.

White House officials say Mr. Bush's letter urged Kim Jong Il to make a full and accurate declaration of its nuclear activities, and said the U.S. will know if North Korea leaves the declaration incomplete.

Cheon Ho-seon, a spokesman for South Korean President Roh Moo-hyun, says South Korea played a significant role in the White House decision to send the letter. He says U.S. envoy Hill did not have the letter when he was in Seoul, shortly before leaving for North Korea. He says the idea to send the letter arose during Hill's consultations with South Korean officials.

The White House has not released the full contents of Mr. Bush's letter to Kim Jong Il, but say it underscores Washington's view that the six-nation negotiations are at a critical juncture.