Seoul, South Korea ? United Nations inspectors have verified that North Korea has shut down its sole functioning nuclear reactor, the chief of the watchdog agency said today, confirming the isolated country had taken its first step in nearly five years to halt production of atomic weapons.

South Korea sent more oil to the North today to reward its compliance with an international disarmament agreement.

“Our inspectors are there. They verified the shutting down of the reactor yesterday,” said Mohamed ElBaradei, chief of the U.N. International Atomic Energy Agency.

“The process has been going quite well and we have had good cooperation from North Korea. It’s a good step in the right direction,” ElBaradei said in Bangkok, where he was to attend an event sponsored by Thailand’s Ministry of Science.

South Korean Unification Minister Lee Jae-joung said a second shipment of oil departed today for the North on a ship. A first shipment that arrived Saturday – prompting the North to follow through on its pledge to shut the reactor – has been completely offloaded, Lee said at a meeting with U.S. nuclear envoy Christopher Hill.

The two shipments are part of 50,000 tons of oil that the North will receive for the reactor shutdown. Under a February agreement at international arms talks, North Korea will receive a total equivalent of 1 million tons of oil for dismantling its nuclear programs.

A North Korean diplomat said Sunday that his country was willing to discuss disclosing the full extent of its nuclear programs as well as disabling them as long as the U.S. removed all sanctions against the impoverished country.

Hill said today during his meeting with Lee that Washington moving to remove the North’s pariah status would depend on the North’s continued compliance with its disarmament promises.

“With complete denuclearization, everything is going to be possible,” Hill said.

The North said it shut down the reactor, which generates plutonium for atomic bombs, on Saturday. It was the first on-the-ground achievement toward scaling back the country’s nuclear ambitions since an international standoff began in late 2002.

The North’s Foreign Ministry said Sunday that further progress on disarmament would depend “on what practical measures the U.S. and Japan, in particular, will take to roll back their hostile policies toward” North Korea. North Korea wants normal relations with both countries.