Japanese business leaders urged the government Wednesday to work hard to make the Kyoto Protocol, which took effect Wednesday, an effective international treaty.

"We want the Japanese government to take leadership in establishing an international framework (for the protocol) at an early time," Japan Business Federation (Nippon Keidanren) Chairman Hiroshi Okuda said in a statement.

Some critics say the pact is toothless because China, India and other developing countries are exempt from the treaty's obligations to curb greenhouse gases. The United States, which accounts for 40 percent of the world's greenhouse gas emissions, withdrew from the protocol in 2001 after saying the pact would harm its economy.

Kakutaro Kitashiro, chairman of the Japan Association of Corporate Executives, joined Okuda, saying, "A broad framework is necessary for the pact."

Kitashiro called for Japan to put its environment-related technologies to good use.

"Japan has the world's top-level environmental technologies," he said. "Japan should further push for technological innovation and disseminate technological achievements to the world in order to make the pact globally effective."

To fulfill the country's commitments under the pact, Okuda said Japan should come up with policies that respect individual and corporate creativity, rather than tighten regulations such as by imposing an environment tax.

Nobuo Yamaguchi, chairman of the Japan Chamber of Commerce and Industry, accused the government of accepting the Kyoto Protocol although its conditions are disadvantageous for Japan. He called it "a diplomatic failure."

Japan is required to cut greenhouse gas emissions by 6 percent from 1990 levels between 2008 and 2012.