The four-person team from the International Atomic Energy Agency, the UN's nuclear watchdog, has been tasked with arranging the shutdown of the North's nuclear reactor at Yongbyon.
North Korea vowed on June 25 to move forward with an agreement to shut down the reactor in exchange for aid, after announcing that a dispute over frozen bank funds that had held up disarmament efforts was now finally over.
The North had refused to comply with the February agreement to shut down Yongbyon until it received the $25 million, which the United States had linked to money laundering and counterfeiting.
"We are always needing to be optimistic. I think the DPRK will now do what they have [been] asked to do," Olli Heinonen, chief nuclear inspector for the IAEA, told reporters in Beijing before flying to Pyongyang.
As the UN inspectors flew in, a delegation from the European Parliament ended its visit to North Korea expressing optimism that Pyongyang would dismantle its nuclear program.
The head of the delegation, Austrian lawmaker Hubert Pirker, said North Korean officials had expressed willingness to implement the February agreement.
Separately, South Korea responded to Pyongyang's move by saying today it would resume rice aid to its impoverished neighbor on June 20.
Food aid was suspended after North Korea defied international warnings and test-fired missiles in July 2006.
First Step In Deal
The closing of Yongbyon in exchange for fuel oil is the first step of the February deal.
The eventual goal is for the North to completely scrap its nuclear program in exchange for aid, security guarantees, and better diplomatic standing.
The agreement was reached in talks involving China, Japan, Russia, the two Koreas, and the United States.
(compiled from agency reports)