President Bush today pledged to use science and diplomacy to fight global warming as he tried to blunt international criticism over his rejection of the Kyoto climate treaty before he visits Europe.
But Mr Bush offered no mandatory or specific targets to contain the problem, which is sure to disappoint many Europeans he is to meetthis week.
"My administration is committed to a leadership role on the issue of climate change," Mr Bush said only hours before he was to leave on his first presidential visit to Europe.
Many European leaders have criticised his rejection of the 1997 Kyoto treaty, which obliges industrial nations to reduce emissions of carbon dioxide and other greenhouse gases thought to cause global warming.
"We recognise a responsibility to reduce our emissions", Mr Bush said. But he again rejected the Kyoto treaty's mandatory targets as harmful to the US economy, and said developing countries such as China and India must also participate in solving global warming.
Europeans have said mandatory reductions of greenhouse gases are essential to controlling the gradual warming of the earth's temperature.
European Commission President Mr Romano Prodi said in Luxembourg today he hoped the US would show a constructive flexibility in attitude on climate change.But it should be along the lines of the framework of the Kyoto protocol, he said.
Meanwhile the head of the United Nations climate change forum offered new proposals to the stalled talks on cutting global warming gases, including a measure aimed at firming up support in Japan.
The new plan was the second this year from Dutch Environment Minister Mr Jan Pronk, the head of the UN panel, and aimed at jump-starting international talks set to resume next month in Germany after the US rejection last year.
"Global warming is a real problem", Mr Bush said, "but it remains uncertain how much of it is caused by humans" - a contention disputed by environmentalists who say human activity is a big enough cause to warrant immediate action.