WASHINGTON - European Union leaders are looking for momentum on a global climate change deal out of a summit with President Barack Obama on Tuesday.

The White House meeting comes just a month ahead of a global meeting on climate change in Copenhagen as world leaders negotiate a follow-on agreement to the Kyoto Protocol.

Before the White House meeting, European Commission President Jose Manuel Barroso said that forging a climate deal is "a defining moment" for his generation of world leaders.

Barroso told reporters in Washington that he was worried by the lack of progress on the climate deal and that a final agreement was unlikely in Copenhagen. But he dismissed the suggestion that leaders should aim for a watered down treaty to get some result. Instead, he said he hoped that leaders could agree on the outlines of an ambitious agreement to be hammered out in detail later.

"If you start to speak of plan B in Copenhagen, you will probably end up with plan F," he said.

Barroso said that European leaders are looking for a strong U.S. contribution to an international aid fund that would help developing nations adapt to climate change.

The European Union on Friday called for euro5 billion to euro7 billion ($7.5 billion to $10.3 billion) in climate change aid to poorer nations over the next three years, reaching euro100 billion, or nearly $150 billion a year, by 2020.

"Certainly we would like to see what the United States can contribute," Barroso said.

Tuesday's summit will touch on a range of issues beyond climate change. Barroso said he expected discussion on economic management, Afghanistan, Iran and Middle East peace among other topics.

The EU will also be represented by the prime minister and foreign minister of Sweden at the meeting, which will begin with a lunch hosted by Vice-President Joe Biden.