Environment Agency chief Yoriko Kawaguchi has praised Japan's global warming measures and hinted at the need for more action by the United States going into international climate change negotiations next month in the Netherlands.

Speaking Wednesday in Tokyo at the Foreign Correspondents' Club of Japan, Kawaguchi focused on global warming issues. She played up domestic initiatives, contrasting the nation's emissions with those of the U.S., the world's largest emitter of greenhouse gases.

"The Japanese government, in its efforts to bring the Kyoto conference to a successful close, opted for a domestically difficult policy to reduce emissions in what was a lean system to begin with," Kawaguchi said.