French, Swedish and Polish leaders have praised British Prime Minister Tony Blair, who led the talks and secured agreement on a budget of around 1,400 billion dollars.
Poland was celebrating a deal which gives it an additional two billion dollars in aid.
Germany's new Chancellor Angela Merkel was reported to have played an important role in securing the compromise deal.
She described it as "a good accord for the future of Europe".
Under the deal, Germany, the UK and France, along with other wealthier EU countries, will have to pay increased contributions to help pay for the 2004 enlargement of the trading bloc.