The United Nations rejected Prime Minister Shinzo Abe's request to speak at its climate summit last September, government sources said Thursday, apparently due to the government's promotion of coal-fired power plants.

Abe had wanted to brief participants at the U.N. Climate Action Summit on the outcome of the Group of 20 summit in Osaka in June, said the sources, who added the U.N. response may also have been prompted by Japan's failure to upgrade its goals for greenhouse gas emissions cuts.

"This had to be a summit of action plans, not platitudes," U.N. Secretary-General Antonio Guterres said in his closing remarks at the climate summit in New York on Sept. 23.