A US senior official said today that Washington wants Pyongyang to declare all its nuclear programs before the launch of South Korea's new government on Feb.25, South Korea's Yonhap News Agency reported.

US Assistant Secretary of State Christopher Hill made the remarks after meeting with South Korea's incoming president Lee Myung-bak in Seoul.

It is very desirable for Pyongyang to complete the declaration even before Lee takes office so negotiators can focus on the last phase by the time Lee's government begins its term, Yonhap quoted Hill as saying.

"It is a tougher issue than maybe it should be. I mean tougher from a psychological point of view," he said. "That is why I think we need to show a little patience with the situation."

Hill said he had a "very good discussion" with Lee about the need to work closely together for denuclearization of the Korean Peninsula.

Hill, who ended his three-day visit in Seoul and left for Beijing today, said he will discuss the timing of a new round of six-party talks with his Chinese counterpart Wu Dawei later today.

During Hill's stay in Seoul, he met with President Roh Moo-hyun, Foreign Minister Song Min-soon, and Seoul's top nuclear envoy ChunYung-woo.

At the meeting with Chun, Hill and Chun both agreed to push for a quick resumption of the six-party talks.