Japan has offered to provide $10 billion (£6.16 billion) over the next three years as part of an aid package to help developing nations deal with climate change.
According to a report by Reuters, prime minister Yukio Hatoyama will officially announce the pledge on the final day of the Copenhagen Climate Change Conference.
The news provider commented that any deal on climate change and emissions reductions is likely to hinge on the amount of money donated by developed countries to help their poorer neighbours.
Earlier this week, the European Union announced that it would provide $10.5 billion until 2012, when contributions will gradually be scaled up.
Britain's contribution to the fund now stands at £1.5 billion after Gordon Brown dramatically increased the level of aid available at the end of last week.
Talks are continuing as politicians and world leaders attempt to reach an agreement on global emissions reductions coupled with financial support for developing nations before the conference ends on Friday December 18th.