Environment chiefs from top industrial countries called Monday for an agreement on cutting greenhouse gas emissions in half by 2050, declaring that developed nations should take the lead in battling global warming.

The statement by ministers from the Group of Eight nations, aimed at preparing for action on climate change at the G8 summit in Toyako, Japan in July, also acknowledged calls for midterm emissions reduction targets for 2020, though it did not specify any goals.

The three day meetings of G8 ministers — from Japan, the United States, Germany, France, Italy, Canada, Britain and Russia — and observer countries also strove to revive momentum for wider U.N.-led talks on a new global warming pact.

"The major outcome was on climate change: We strongly expressed the will to come to agreement at Toyako so we can halve emissions by 2050," Japanese Environment Minister Ichiro Kamoshita said. "Advanced nations should show leadership to reach this goal."

The statement cited the need for global gas emissions to peak within the next 10 to 20 years, and it called on developing countries with rapidly expanding greenhouse gas emissions to work to curb the rate of increase.

While signaling the need for midterm targets, the ministers made only an indirect mention of a U.N. scientific finding that rich countries should make reductions of between 25 percent and 40 percent by 2020 to avoid the worst effects of warming.

"The need was expressed for effective midterm targets which take into account the findings of the IPCC," the statement said, referring to the Intergovernmental Panel on Climate Change, which shared last year's Nobel Peace Prize with former U.S. Vice President Al Gore.

European nations, the U.N. climate chief and environmentalists had clamored in Kobe for progress toward such a reduction pledge by G8 countries, arguing that failure could endanger the U.N. talks, which face a December 2009 deadline.

"Without a mandatory midterm target for developing countries, it will be very difficult to get agreement" by that deadline, said Matthias Machnig, the delegate from Germany. Still, he conceded that ministers in Kobe had "made a step here today — a small one, but an important one."

The European Union has pledged a 20 percent emissions reduction by 2020 and has offered to raise it to 30 percent if other nations sign on. The United States, however, has not committed to a midterm goal, demanding commitments from top developing countries such as China first. Japan has also not yet set a 2020 target.

Kamoshita and Scott Fulton, deputy assistant administrator at the U.S. Environmental Protection Agency, argued that it was premature for them to set midterm targets, and they said such commitments should be the result of negotiations leading to the climate pact in 2009.

"At this point, I'm not sure if it's appropriate for us to cite specific figures," Kamoshita said.

The United States is the only major industrialized country not to have ratified the Kyoto Protocol global warming pact, which commits 37 nations to cutting emissions by an average of 5 percent below 1990 levels by 2012. Washington has argued that the pact would hurt its economy and is unfair because it does not obligate developing nations to also cut emissions.

During a news conference after the concluding meeting, divisions were apparent between Germany and the United States. Machnig forcefully described Germany's commitment to cutting gases by 40 percent by 2020, several times turning in Fulton's direction as he spoke.

Fulton, who also called for commitments from heavily polluting emerging economies, defended U.S. action on climate change, citing billions of dollars spent on environmental research and other anti-warming steps.

"We've not been sitting on our hands by any means," he said.

The ministers also nodded to developing nations' demands for help in financing and technology transfer to become more energy efficient, grow their economies more cleanly, and adapt to changes wrought by warming, such as rising sea levels.

The meeting in Kobe took place amid fears by some that the momentum was draining from the U.N.-led talks on a new climate pact to take over when Kyoto's first phase expires in 2012. The talks have struggled to overcome divisions between rich countries concerned about growing emissions in the developing world, and poorer nations who argue industrialized countries must take the first steps to address warming.

U.N. climate chief Yvo de Boer said rich nations needed to set national targets — in addition to global goals — as a clear signal to businesses.

"If you're a businessman or woman in any country of the world and you're about to build a $500 million power plant, then a global goal doesn't tell you what investment choice to make," he said. "But if you know the country that you're in plans to reduce emissions by `X' percent by 2020, you're going to want to be part of the solution, not part of the problem."