In an address at the United Nations this week, Prime Minister Yukio Hatoyama will officially pledge that Japan will drastically cut its greenhouse gas emissions while promising vigorous support for developing countries in climate technology and funding.

The enhanced support for developing economies under the tentatively named "Hatoyama Initiative" is aimed at ensuring a leading role for Japan in discussions on an international framework for curbing emissions from 2013 that will succeed the Kyoto Protocol, a government official said over the weekend.

The initiative centers on extending Japan's technological knowhow on energy conservation. But Hatoyama may fall short of pledging how much Japan will commit financially to developing countries because the amount required will likely be substantial and where it will come from is very much an open question.