Top U.S. negotiator Christopher Hill said here Tuesday that it was proving difficult to settle the dispute over funds belonging to the Democratic People's Republic of Korea (DPRK), a crucial obstacle to having the country shut down its nuclear reactor.

Under a February agreement reached at six-party talks on the Korean Peninsula nuclear issue, Pyongyang agreed to move to scrap its nuclear weapons program but has demanded the frozen funds of 25 million U.S. dollars in a Macau bank be transferred first.

An American bank Wachovia has said that it had agreed to accept the transfer pending regulatory approval.

"We had worked those for several weeks and then we find out it does not work and so we have to erase the steps and find something else. So it is proved to be very difficult," Hill told reporters after meeting with Indonesian Vice President Jusuf Kalla, Defense Minister Juwono Sudarsono and several parliament members.

He said although the amount of the money was obviously small in the overall schemes at the denuclearization, but it has strong relation with the implementation of the February agreement.

"We do not want to create a situation with the DPRK, (and make the country) try to get out of the obligation that already has in six-party process to create another process that can somehow change the rules of the games and lose a lot of time," he said.

Indonesia has asked all concerned parties to smooth the payment of the DPRK's funds in return for the country's commitment to close its nuclear reactor.

Hill, who is also the Assistance Secretary of State for East Asian and Pacific Affairs, said he expected Indonesia, which historically has had friendly ties with Pyongyang, to play a role in urging the DPRK to meet its commitment.

"We value Indonesia's role very much and it has been very good for us," he said.