The United States Thursday urged North Korea to honor pledges to scrap its nuclear weapons program, despite a breakdown in talks to end the program, blaming a "technical issue" for the collapse.
"We expect them to live up to their commitments but, at this point, this is not an issue of American unwillingness. It's a technical issue in terms of fund transferring," said White House spokesman Tony Snow.

He was referring to demands for the return of 25 million dollars of North Korean assets, which have been frozen in a Macau bank since 2005 over US accusations of money laundering and counterfeiting. Pyongyang's envoy to the nuclear negiotiations has refused to talk until the money is transferred.

The issue has delayed efforts to implement a multinational deal struck in February, under which the North would shut down its nuclear programs and admit United Nations nuclear watchdog inspectors in exchange for economic and diplomatic benefits.

The United States said it had struck a deal to release all the assets frozen in the bank, Banco Delta Asia.

"In other words, we've done our part. So at this point it's a technical issue," said Snow.

The money was not sent from Macau to a North Korean account in Beijing as expected, leaving the envoys frustrated. The talks then ended without agreement on Thursday after four days of deadlock, with no date set for their resumption.

A statement released by host nation China on Thursday said the six nations involved in talks on the nuclear issue remained committed to implementing the February accord.

Under this deal, North Korea would shut its Yongbyon reactor within 60 days of that agreement in return for 50,000 tonnes of fuel aid.

State Department spokesman Sean McCormack said on Thursday that the six nations -- the two Koreas, China, the United States, Japan and Russia -- would likely meet again soon.

"They will probably get together again in the next week or two as we get closer to the 60 days clock ... at the envoy level," he said.

"The North Koreans continued to reaffirm their commitment to meet the February goals" during earlier talks of representatives of the six in Beijing, including the US top envoy Christopher Hill, McCormack said.

"All the parties are optimistic about the process and being able to meet the 60 days clock," he added.

Hill said on Thursday morning that the money transfer should not have been a reason to hold up the talks. "This was a procedural, form-filling issue," he said.