"The question is how and by what way can the DPRK (North Korea) get the money and realise the normal transfer of the funds," foreign ministry spokesman Liu Jianchao told reporters.

"There are still some technical issues on this question."

North Korea missed an April 14 deadline to shut down its Yongbyon nuclear reactor under a February six-nation accord, saying it would only do so once it received 25 million dollars that had been frozen in Macau's Banco Delta Asia.

The United States blocked the funds in Banco Delta Asia in late 2005 after accusing North Korea of money laundering and counterfeiting but agreed -- following the February accord -- to release the money.

The United States said last month that money was now available for North Korea to withdraw, but the issue remains outstanding.

Other banks reportedly are unwilling to touch the money because the United States had originally said it was contaminated and they believe the decision to release the money was made for political rather than legal reasons.

Despite the continued delays, Liu insisted that North Korea and the other five nations in the six-party talks remained committed to the February agreement.

The February agreement calls for North Korea to shut down its nuclear plant and invite international nuclear inspectors to the facility in exchange for 50,000 tonnes of fuel oil and talks on diplomatic recognition.

Following this "initial phase," up to 950,000 tonnes of oil or aid equivalent would be offered to North Korea in exchange for the complete dismantling of all its nuclear programmes.

The six-party talks, which involve China, the two Koreas, the United States, Japan and Russia, began in 2003 with the aim of ending Pyongyang's nuclear ambitions but have been plagued by long delays and setbacks.

They also failed to stop North Korea from conducting its first test of an atomic bomb in October last year.