Fiscal constraints continued to push down Japan's official development assistance, leaving the country in fifth place in 2007, according to the white paper on ODA submitted Tuesday to the Cabinet.

Net bilateral ODA disbursements in 2007 marked an annual drop of 31 percent to approximately $76.79 billion. A top donor in the 1990s, Japan now ranks behind the United States, Britain, Germany and France, the report says.

But the government remains certain that overseas assistance will be a key diplomatic tool for the country and pledged to fulfill agreements reached at last year's Tokyo International Conference on African Development and the Group of Eight summit in Toyako, Hokkaido.

"Aid to Africa and assisting climate change issues will be the distinctive feature of Japan's ODA," a Foreign Ministry official told reporters in presenting the annual report compiled by the ministry.

The centerpiece of Japan's environmental aid will be the "Cool Earth Partnership" mechanism, which pledges approximately $10 billion to developing countries over five years, according to the report. The system, which seeks to make environment preservation and economic development compatible, will focus on supporting nations' efforts to nurture efficient energy use.

"Climate change will continue to be one of the principal issues on assisting development" of other nations, the white paper says.

On aiding impoverished African countries, the report says nurturing economic ties by stabilizing the "natural resource rich" continent benefits Japan. It also points out the merit of advancing ties with Africa.

Africa remained the top recipient of Japan's ODA in 2007, receiving 29.4 percent of disbursements. It topped Asia as the biggest beneficiary of Japan's ODA in 2006.

"To remain a bystander on African development is not only unacceptable, but also not in the national interest," the report says.