TOKYO Japan is hoping the European Union will soften its line on climate change so that the United States will agree to back an international accord to fight global warming, AFP quoted Environment Minister Yoriko Kawaguchi as saying on Wednesday.

Despite opposition from the United States -- which alone produces a quarter of all worldwide emissions of the greenhouse gases blamed for global warming -- a compromise deal is still possible to allow the UN treaty, the so-called Kyoto Protocol, to enter into force by 2002, Kawaguchi said.

"Japan is hoping to get the EU to soften its stance on certain points ... to maximize the chances of bringing the U.S. back into the Kyoto Protocol," she told the Foreign Correspondents' Club of Japan.

Signed in 1997 in the Japanese city of Kyoto, the UN treaty commits 38 industrialized countries to bringing their output of six greenhouse gases to 5.2 percent below their 1990 level by a deadline of 2008-2012.

The protocol says countries may reach their legally-binding targets for cutting emissions by actually cutting pollution at home or, more controversially, by "trading" emissions with other countries via so-called "flexible mechanisms".

Bush announced in March the U.S. would not ratify the protocol, contending it was "unfair" to the U.S. economy.

"The Kyoto Protocol is like a house being built" with all the basic framework ready, Japan's Kawaguchi said. "What we are looking at now is finishing up smaller details, trying to decide whether to plaster the walls or paper them."

"We all need to approach these issues with flexibility and a spirit of cooperation," she said.

EU leaders said at their summit in Gothenburg, Sweden, last weekend that they were committed to ratifying the Climate Change Treaty by the end of the year, despite U.S. President George W. Bush rejecting the protocol as fatally flawed.

Washington too stuck to its guns, with U.S. Secretary of State Colin Powell on Sunday describing the Kyoto Protocol as a "dead letter".

"I have to say I certainly was and am disappointed that Mr. Bush said that he does not support the Kyoto Protocol," Kawaguchi said.

But she said "the use of market mechanisms" such as emissions trading could be one way to bring more flexibility and strike a compromise deal.

She noted the EU had originally said countries could trade away only two percent of their greenhouse gas reduction targets but Japan believed the trading quotas could be as much as 30 percent.

The minister also said there could be more "constructive" measures to ensure compliance with the legally-binding reductions targets.

Countries which could not meet their targets could be offered advice in the form of "policy options" to help them do so in future rather than be required to pay penalties, she said.

The EU is expected to send a high-level mission around the world, including to Japan to push for ratification of the UN treaty.

The protocol cannot enter into force until it is ratified by a significant percentage of the original signatories.

"The importance of America's participation is not something that we can downplay (but) you need to understand there is still a good deal of maneuvering room here," Kawaguchi said.

Countries "should actively draw on the wisdom of friends and allies and you have a very positive atmosphere in which Japan and other nations do have a good window of opportunities to shift American policy," she said.

Kawaguchi said she hoped to attend a ministerial meeting in The Hague next week to prepare for a top-level conference of signatory countries (COP6) in Bonn, Germany, on July 16-27.

The Hague meeting represents the "last chance to work out our differences" before the Bonn conference, she said, adding she wanted to visit the United States before Bonn.

The leader of Japan's largest opposition Democratic Party, Yukio Hatoyama, said during parliamentary question time on Wednesday that Japan should ratify the treaty without waiting for the United States. If Tokyo did so, the number of countries ratifying the protocol would be sufficient for it to enter into force on time in 2002.

But Prime Minister Junichiro Koizumi said it was not yet time to conclude the process, pledging patiently to work to persuade the United States to back the treaty.

"Relations with the United States, the EU and developing countries are at a very delicate and difficult phase... Each country has its real intention and official position," Koizumi said.