The work relates to shutting down North Korea's main nuclear facilities, the paper said.

The experts will join two specialists from Russia and China to inspect the five-megawatt reactor at Yongbyon and fuel production and recycling facilities, the first visit by foreign experts since a delegation from the United Nations nuclear watchdog, the International Atomic Energy Agency, verified the shutdown of the country's only operational rector in July.

A U.S. administration source said Pyongyang's invitation was a serious move towards implementing the second stage of a deal that the North reached in February with the U.S., China, Japan, South Korea and Russia, which are involved in six-party talks on the North Korean nuclear issue. Under the agreement reached in Beijing, North Korea agreed to permanently disable its nuclear facilities and provide a full account of its nuclear weapon activities.

In exchange the North will receive 950,000 metric tons of fuel oil for its thermal power-generating plants, in addition to the 50,000 already delivered for the reactor's closure.

The February agreement was considered a breakthrough following more than three years of negotiations since Pyongyang withdrew from the Non-Proliferation Treaty in 2003 and conducted a nuclear bomb test last October. - RIA Novosti