WASHINGTON, April 30: US President George W. Bush and visiting European leaders agreed on Monday to define global warming as a serious problem requiring “urgent” action, but deadlocked on what concrete remedies to apply.

“I think this is where we should be clear about the glass being half full instead of half empty,” German Chancellor Angela Merkel said at a joint public appearance on the sidelines of the annual US-EU summit at the White House.

Merkel, who holds the rotating presidencies of the EU and the Group of Eight (G8) industrialized nations, spoke after talks with Bush and European Commission President Jose Manuel Barroso.

The three leaders formed a united front on Iran's nuclear programme, which Washington says is cover for an atomic weapons quest. The United States has backed talks led by Britain, France and Germany.

“We talked about Iran and the need for our nations to continue to work closely together to send a unified message to the Iranians that their development of a nuclear weapon is unacceptable to peace,” said Bush.

“Nuclear proliferation is indeed a threat, not only to regional stability but to the global peace and global stability,” said Barroso. “And the Iranians should understand that this message they are receiving.” In a joint statement on energy security and climate change, the three leaders called for “urgent, sustained, global action” to battle global warming.

Asked what concrete steps they had agreed to take, the leaders said they had set up a US-EU conference on alternative-fuel standards to meet in here next year, and plans to take up climate change at the June G8 summit in Germany.

Merkel also said they had agreed on the need for “a proper agenda” for UN talks on the environment in December on the Indonesian island of Bali, calling that “an enormous step forward.” Bush, who declared “the good news is that we recognize there's a problem,” said no solution is possible unless it includes major developing nations like

China and India but seemed to say that Washington would find its own way.

“I think that each country needs to recognise that we must reduce our greenhouse gases and deal, obviously, with their own internal politics to come up with an effective strategy that hopefully, when added together, that it leads to a real reduction,” he said.

Bush called earlier this year for a 20-per cent cut in gasoline use over 10 years, citing advances in the use of alternative fuels, and for the US Congress to broaden his powers to overhaul emissions standards.

The 27 EU members agreed in March to reduce greenhouse gas emissions by at least 20 percent by 2020, based on 1990 levels. Germany's proposal was a more aggressive 40 percent cut.

“There are different approaches, obviously, as to how to solve that. But we have been able, actually, to find a lot of common ground,” Barroso said at the White House.

Merkel said any solution had to cover developing countries but warned “what is also true is that, if the developed countries, who have the best technology, don't do anything, it will be even harder to convince the others.

“But without convincing the others, CO2 emissions worldwide will not go down,” she said.

The leaders also said they had discussed efforts to revive the Doha Round of global trade talks; reconstruction and development efforts in Iraq and Afghanistan; Cuba's future; and the Middle East peace process.

“We have been talking at greater length also about the situation in Darfur, which we consider to be totally unacceptable, and that we need to do everything we can in order to help the people there,” said Merkel.

“We ought to use all of our possibilities in order to achieve progress also in the United Nations,” she said.—AFP