Talks on releasing North Korea's funds that have held up international efforts to disarm Pyongyang have ended in China's capital with no resolution.

The U.S. Embassy in Beijing said Friday the United States is still confident that a fast-approaching deadline in the disarmament process will be met. An embassy spokesperson said Washington is continuing to work with all parties involved to meet the April 14 deadline for North Korea to close its main nuclear reactor and to allow inspectors in the country.

North Korea agreed to the steps in a breakthrough nuclear agreement in February. In exchange, Pyongyang was promised energy aid and diplomatic incentives.

However, a dispute over $25 million in North Korean funds, frozen at a bank in Macau, continues to be one of the biggest obstacles to moving that agreement forward.

The money was frozen two years ago after Washington accused Macau's Banco Delta Asia of helping North Korea launder money.

The State Department spokesman acknowledged that transferring the money has been more complex than was initially thought.

U.S. Treasury officials have been in Beijing since last week, trying to arrange the transfer of the funds.

North Korea's delegation walked out of the six-party nuclear talks last month and said it would not return until the funds are transferred.

Some information for this report was provided by AFP and AP.