SEOUL - A team from the UN nuclear watchdog agency arrived in North Korea on Saturday ahead of a planned shutdown of its atomic reactor under a disarmament deal and just hours after delivery of a promised cargo of fuel oil.

International Atomic Energy Agency (IAEA) chief of mission Adel Tolba speaks to the media as he leaves for North Korea at Beijing's airport July 14, 2007. [Reuters]

On arrival in Pyongyang the team from the International Atomic Energy Agency (IAEA) declined to answer questions from waiting reporters, the Chinese news agency Xinhua reported.

North Korea said last week it would consider suspending the operation of its nuclear facilities as soon as it received the first shipment of oil from South Korea under the February 13 aid-for-disarmament deal.

A South Korean tanker carrying 6,200 tons of fuel oil arrived early on Saturday at the port of Sonbong on North Korea's northeastern coast, the Unification Ministry in Seoul said.

It was the first installment of a 50,000-tonne oil shipment North Korea is to receive under the February agreement in return for shutting its reactor at Yongbyon, north of Pyongyang, and admitting an IAEA team to help monitor the closure.

It will be the first time the North Korea's nuclear activities have been under outside surveillance since late 2002.

The leader of the IAEA team said earlier in Beijing they would be going straight to Yongbyon on Saturday to begin work at the complex, which produces weapons-grade plutonium.

"We are en route to Yongbyon facilities," Adel Tolba told reporters before boarding the flight to Pyongyang.

"We have our equipment with us. We will resume our work when we arrive."

North Korea had informed China that the reactor would be shut down on Monday, the Japanese daily Asahi Shimbun reported, quoting a source involved in six-country talks aimed at ending North Korea's nuclear ambitions.

A Chinese Foreign Ministry spokesman said Beijing was unaware of a date for the shutdown and believed this would be a topic when the six-way talks resume in Beijing on Wednesday.

The talks, at which North Korea sits down with the United States, South Korea, China, Japan and Russia, are expected to map out the next stage of the disarmament process.

The five have promised massive economic aid and better diplomatic ties if Pyongyang scraps its nuclear arms program.

IAEA director Mohamed ElBaradei has said it would take about a month to complete setting up the monitoring equipment.

In 2002 the United States accused North Korea of operating a covert uranium enrichment program in violation of a 1994 nuclear-freeze deal. In December 2002, the North expelled IAEA inspectors and said it would restart its reactor. It conducted its first nuclear test in October 2006.