George W Bush has sparked anger and raised the prospect of a deep rift with Europe after he declared his "unequivocal" opposition to the Kyoto accords.

"[It] makes no economic sense. It makes no common sense," he said.

The climate change row came as the US president met German chancellor, Gerhard Schroder, who is in coalition with Greens. Schroder told Bush that America must accept responsibility for the planets climate and described the resulting exchange as "frank".

America's opposition now puts the future of the controversial Kyoto Treaty in jeopardy. Whilst no major European nation has ratified the treaty so far, EU states believe it would be the best framework for tackling climate change.

The threat to the treaty has been described as "exceptionally serious" by environment minister, Michael Meacher.

Ruling out the possibility of trade sanctions against the economic superpower, Meacher said that the UK and EU should still go ahead with plans to ratify the accords in 2002.

"I think the EU and the UK should still proceed to ratify the protocol in 2002, because that's the only way to stop global warming," he told the BBC.

Speaking on Sky News, the minister said that there was cause for optimism with the battle over climate change far from over, not just in the international community but in America too.

"We don't accept that it is a situation in which we just despair. First of all, clearly there are voices in the US administration, particularly in the state department, who take a very different view. I would say there is something of a power struggle going on and we should seek to lobby those who do share our view to have greater influence," he said.

Promising that EU countries would put direct arguments to Bush at EU and G8 summits in July, Meacher said: "That will be an opportunity to put personally what I believe will have to be, very strong pressure. This is not just an environmental issue. We are talking about a transatlantic and global foreign policy issue."

EU environment chief, commissioner Margot Wallstrom, told Radio 4's Today programme of her upset and disappointment at the US stance.

Vowing to fight on at the resumed COP6 climate change talks in Bonn this July, she said: "I think we have to make it absolutely clear to the United States that this is also about international relations. This is about trade and this is about the economy."

Underlining that US must operate in an international framework dictated in part by the EU, the commissioner warned the US that: "We have to make it clear that also big businesses and multi national companies are very interested in the decisions to be made in Bonn and that we are involved in creating the operational rules for the Kyoto Protocol."

"It is not something you can simply pull out of. There is an obligation also to talk to us. They (the US) are trading partners as well as partners in international negotiations," she said.

The debate over climate change is not a straightforward one and has always been dogged by controversy. To begin with, scientific opinion is still split on whether carbon dioxide and other "greenhouse gases" are the cause of global warming.

The UN's Intergovernmental Panel on Climate Change follows the growing orthodoxy of blaming humans for global warming - claiming the world is heating up more than expected due to industrial activity. Others argue that rising temperatures are part of a natural phenomenon.

A global strategy on climate change was first agreed under the 1992 United Nations Climate Change Convention and its 1997 Kyoto Protocol.

Committing the industrialised world to cut its greenhouse emissions by a minimum of five per cent from 1990 levels by 2008-12, the protocol has been signed by 84 nations to date - and ratified in 33.

No major European nation has ratified the treaty yet and the protocol will only have legal effect after it has been ratified by 55 per cent of the countries which have signed it.

International COP6 talks on finalising the details of Kyoto broke down in The Hague last November, with a very public rift between the US and the EU. They are to be resumed - with or without the US - in Bonn this July.