North Korea has invited United Nations arms inspectors to visit and discuss procedures for shutting down its main nuclear reactor -- a sign of progress in the slow process towards disarmament.

The invitation comes after North Korean funds held up in a Macau bank blacklisted by the U.S. were freed up. The North had promised in February to disarm, but said it wouldn't follow through until it got access to the money.

"A working-level delegation of the IAEA has been invited to visit as it is confirmed that the process of de-freezing the funds at the Banco Delta Asia in Macau has reached its final phase," said a letter to the International Atomic Energy Agency, cited by North Korea's Central News Agency.

The U.S. had accused the bank of helping North Korea's government pass counterfeit $100 bills and of laundering money made from the sale of weapons.

The North said the move was a sign of U.S. hostility, and boycotted nuclear talks for more than a year as a result.

In that period, the nation conducted its first atomic bomb test, raising tensions around the world and in South Korea, the North's closest neighbour.

But the U.S. agreed earlier this year to approve the transfer of funds in an attempt to restart talks.

South Korea's chief nuclear envoy said the Saturday announcement is "good news."

"As we watch how the discussions between North Korea and the IAEA proceed, we will start preparations for implementing our own obligations as outlined by the Feb. 13 agreement," Chun Yung-woo told The Associated Press.

Under a deal reached during the six nation talks between the U.S., China, Russia, Japan and North and South Korea that led to the February disarmament pledge, it was agreed that 50,000 tons of heavy fuel oil would be sent to Pyongyang if it shut down its reactor.

The North also has to allow UN inspectors in to verify the closure and seal the plant, under the terms. It would mark the first time IAEA have worked in the country since December, 2002, when inspectors were kicked out.

There are reports that the transfer of the Macau funds has begun, but has not yet been completed.

With files from The Associated Press