U.S. and North Korean diplomats are meeting in Beijing to discuss North Korea's agreement to declare and dismantle all of its nuclear programs.  Daniel Schearf reports from the Chinese capital.

Washington's chief negotiator at the North Korean nuclear disarmament talks, Assistant Secretary of State Christopher Hill, arrived in Beijing Monday for talks with his North Korean counterpart, Kim Kye-Kwan. 

At the top of the agenda for their Monday meeting is the next stage of a denuclearization agreement reached in February.  The agreement calls for North Korea to provide details of all its nuclear programs, and eventually to dismantle them. 

Hill says he hopes to have Pyongyang's list by late August or early September, when negotiators are scheduled to meet for the next round of six-nation talks.

"We want a clear idea on what's involved in disablement, what's involved in the declaration, so that when we have our meeting, the six-party meeting?we can make real progress," Hill said.

That could prove tricky.  Washington says that in addition to a weapons program based on plutonium, which Pyongyang acknowledges, the North also has a secret program to enrich uranium.

Pyongyang has denied in the past that the uranium program exists.  Hill says the parties to the talks expect a definitive answer this time.

"We have to have clarity on that issue," said Hill.  "We have to have a resolution of that issue.  So, obviously it's very much a part of any declaration that's finally submitted."

The talks will not focus only on what the U.S. and other parties to the talks want.  North Korea expects concessions in return.

It agreed in February to declare and dismantle all its nuclear programs in exchange for aid, security guarantees, and political incentives.  It has already shut down its main nuclear facility.

In return, it has begun receiving shipments of food, fertilizer and fuel oil.  But Pyongyang says it wants at least two light-water nuclear reactors if it gives up its nuclear programs altogether.

The North is also likely to want more than that.  North Korean leader Kim Jong Il is scheduled to meet South Korean President Roh Moo-hyun in Pyongyang at the end of August.  Chung Dong-young, South Korea's former unification minister, said in Seoul Monday that Mr. Kim's main concern is security.

"For chairman Kim and for the North Korean regime, their objective is their [own] survival, and secondly, their economic survival," Chung said.

Chung says he believes Mr. Kim will use the summit to try to secure these guarantees.  But such assurances could not be given by South Korea alone.  They would require input from all six nations involved in the nuclear negotiations, which also include the U.S., Korea, China, Japan and Russia.

Hill and Kim Kye-Kwan are due to continue their discussions during two days of working group meetings beginning Thursday in China's northeastern city of Shenyang.