US technical experts began a rare visit to North Korea to examine ways to disable Pyongyang's nuclear programs, which have produced at least one atomic bomb.
The invitation is seen as a hopeful sign that the North, which tested its first nuclear weapon last October, is serious about permanently shutting down its plants under a sweeping six-nation accord reached in February.
The US team, led by Sung Kim, State Department director for Korean affairs, crossed into North Korea from the South at the border truce village of Panmunjom, the US military said.
Kim and six nuclear technicians were to meet a Russian and a Chinese expert in Pyongyang before beginning a five-day survey of key nuclear facilities.
"The purpose is to survey the nuclear sites to get ready for disablement," Kim told reporters Monday shortly after arriving in Seoul.
The main task is to check on the Yongbyon nuclear complex and decide the most effective way of shutting down the plants permanently.
The team will report back to the next session of six-party talks on North Korea's nuclear ambitions expected this month, which involve the two Koreas, the US, China, Japan and Russia.
After over four years of stalemate, the North agreed in February to declare and disable its nuclear programs in return for aid, security guarantees and major diplomatic benefits. In July it shut down its only operating reactor at Yongbyon in return for fuel oil shipments.
The International Atomic Energy Agency confirmed the shutdown last month, along with the closure of a nuclear fuel fabrication plant, a reprocessing plant and a separate 50-megawatt reactor, only partly built, at Yongbyon.
In addition, a 200-megawatt reactor under construction at Taechon was shut.
The next step is to disable the facilities by encasing them in concrete or some other method -- something the experts will advise on. At a meeting with the US early this month, the North pledged to complete disablement by year-end. If it does so it will receive more fuel oil or the equivalent energy aid.
More importantly, the six-partyaccord accord envisages normalized relations between North Korea and the US and Japan, an end to US trade sanctions and a formal peace treaty on the Korean Peninsula.
But it does not specifically mention any existing nuclear weapons or plutonium stockpiles.
North Korea has enough plutonium to build about five to 12 nuclear weapons, according to various estimates.
However, South Korean President Roh Moo-hyun said yesterday that the nuclear issue was being settled at the multinational talks.
He said the focus of his summit next month with North Korean leader Kim Jong-il in Pyongyang would be to establish a peace agreement on the peninsula, not denuclearization.
"The next stage is the establishing of peace, which is most important," Roh told reporters.