Ministers from the two nations were in Japan, the birthplace of the Kyoto protocol, for an international conference initiated by Tokyo on the "three R's" -- reduce, reuse, recycle -- running until Saturday.

"It is especially important that the USA is reincorporated into the international climate protection process. 4.5 percent of the world's population is responsible for 25 percent of global emissions," German Environment Minister Juergen Trittin said at Keio University in Tokyo.

French Ecology Minister Serge Lepeltier, speaking at the same function here, said that "even US industry leaders are aware that, if they wait too long to take into acount climate change, they will lose the economical competition."

"We may feel paralyzed in front of this huge global challenge, thinking that our efforts have no effect if other countries are not following us," Lepeltier said.

"But I think that in many cases, the first step is often the most difficult. We must continue to be the leaders and others will follow," he said.

US President George W. Bush walked away from the Kyoto treaty as one of his first acts in office, making the United States and Australia the only major industrialized nations not part of the protocol which went into effect in February after Russia's approval.

Kyoto requires industrialized countries which have signed and ratified it to trim output of six carbon gases that linger in the air and trap solar heat instead of letting it radiate back into space.

Bush argues Kyoto would unfairly punish the world's biggest economy by not requiring emission cuts by developing countries such as China and India.

Some 20 countries and four international organizations are taking part in the Tokyo conference, which was proposed by Prime Minister Junichiro Koizumi at last year's Group of Eight industrialized nations summit in the United States.

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