The top U.S. nuclear envoy Christopher Hill is visiting Seoul ahead of a new round of the six-way nuclear talks opening in Beijing this week.

He arrived in Seoul Sunday for talks with Unification Minister Lee Jae-joung and chief nuclear negotiator Chun Yung-woo Monday.

They are expected to discuss how the North can swiftly disable its nuclear facilities and declare all of its nuclear programs.

They will also talk about suspicion over Pyongyang's uranium enrichment program and how to link the matter with energy assistance to the impoverished state.

Hill will fly to Beijing Tuesday for bilateral talks with his North Korean counterpart Kim Kye-kwan.