Chief U.S. nuclear negotiator Christopher Hill arrived in Pyongyang on Monday in the latest U.S. effort to inspect the disablement of the main nuclear facilities in North Korea.

Hill, also U.S. assistant secretary of state, told Xinhua at the airport that he will focus on the issue of Pyongyang's declaration on its nuclear program during his second trip here in six months.

Hill made the trip amid rising doubts about when and how North Korea will dismantle its nuclear program.

"We are getting to the end of phase two, it's been a very important phase," said the head of the U.S. delegation at the six-party talks, adding "we need to make sure it ends very well."

He is going to brief the North Korean side on "what we're doing and should do for fulfilling our responsibilities," said Hill, who was greeted at the airport by a deputy director of North Korean foreign ministry's America bureau.

"I'm going to be trying to get a briefing on how North Korea is doing on its responsibility... and looking forward to seeing the declaration soon," he added.

Hill said he is going to Yongbyon Monday to see how the disablement is progressing.

North Korea said last Friday that it is fulfilling its obligation on the disablement of the Yongbyon nuclear facilities under the agreement reached at the six-party talks.

Regarding the alleged uranium enrichment program and when North Korea will make a declaration of dismantling its nuclear program, Hill said "we'll continue to have a discussion on that, with the understanding that we can resolve this matter by the end of the year."

"I'm hoping that... as we get through this phase, we have something we need to get through including a good declaration," he said.

"We've been working very hard to complete our obligations, and hope that in a year await which is... the last year of the Bush administration, we can complete the process," said Hill.

"That will be a very dramatic improvement in the situation on the Korean Peninsula, and we can begin the process of bringing DPRK into the international community and completing the normalization of ties with U.S.," Hill said, adding "that can only be done in the context of complete denuclearization."

According to a six-party talks joint document released in Beijing on Oct. 3, North Korea agreed to disable all the existing nuclear facilities and provide a complete and correct declaration of all its nuclear programs by the end of this year.

The document said the disablement of the five-megawatt Experimental Reactor, the Reprocessing Plant (Radiochemical Laboratory) and the Nuclear Fuel Rod Fabrication Facility in Yongbyon would be completed by Dec. 31.

(Xinhua News Agency December 3, 2007)