Japan has refused to give fuel to North Korea as promised under a six-nation disarmament deal until Pyongyang does more to account for Japanese nationals kidnapped by the communist state in the 1970s and 1980s to train its spies.

US negotiator Christopher Hill said after a meeting in Washington with his Japanese counterpart Akitaka Saiki that alternatives for Japan have been contacted as efforts were also being made to meet Tokyo's concerns.

'We've been in contact with other countries on it,' Mr Hill told reporters.

A US administration official, speaking to AFP on the condition of anonymity because the talks are sensitive, said that Washington had 'approached' both the European Union and Australia to determine if they could supply the oil.

Mr Hill declined to name the countries contacted outside the framework of the 2007 disarmament deal involving the two Koreas, China, Russia, the United States and Japan.

Under the deal, North Korea was to receive one million tons of fuel oil or equivalent energy aid from the other five countries in return for disabling its plutonium-producing plants.

'We welcome the participation of other countries. So we're proceeding on that basis,' Mr Hill said when asked if Australia or others were being considered to replace Japan.

'Countries have expressed an interest in being part of it,' he added.

'And we're going to work with them and try to see if we can complete the fuel oil deliveries so that we can synchronise that with the disablement activities,' Mr Hill said.

When asked if Mr Saiki said he would accept another country to replace Japan, Mr Hill replied: 'We didn't discuss that except to say that we've been in contact with other countries on it.' Mr Saiki, who was due to join Mr Hill later for dinner, issued no comment to reporters.

In Seoul, a senior South Korean official said earlier this month that the negotiating partners may seek an outside donor to keep the disarmament accord moving forward if Japan persists in withholding its share of energy aid.

Japan was upset with a US decision earlier this month to remove North Korea from a terrorism blacklist before the question of abductions was resolved.

On October 11 the United States struck North Korea from a list of countries which allegedly support terrorism after Pyongyang agreed to steps to verify its nuclear disarmament and pledged to resume disabling its atomic plants.

The agreement appeared to save the disarmament talks from collapse.

However, the United States and its partners are still discussing the verification measures which are to form the basis of a formal verification regime.

Mr Hill said he and Mr Saiki discussed 'ideas about how we might move forward on verification'. He said the partners in the talks were close to settling on a date for a meeting of the main negotiators to formalise the verification regime but 'it's just a very busy time of year right now' and scheduling was difficult.

Mr Hill also said that Mr Sung Kim, the director of the State Department's Korea office, would probably meet with a North Korean delegation due to visit New York early next month. -- AFP