The US President, George W Bush, has said he wants a strong Europe to work with the United States on key international issues.
Mr Bush has been meeting European Union leaders in Washington to discuss transatlantic relations.
EU politicians are denying that the European Union is in crisis despite the failure to agree over the new EU Constitution and a long-term budget for the union.
Meanwhile, Luxembourg is expected to go ahead with plans to hold a referendum on the EU Constitution next month, despite the uncertainty surrounding the charter.
Luxembourg's Prime Minister, Jean-Claude Juncker, who holds the European Union's rotating presidency until the end of this month, has said he will resign if he loses the 10 July ballot.
The 25-nation EU was plunged into crisis three weeks ago when French and Dutch voters rejected the constitution, designed to prevent decision-making gridlock in the expanding bloc.
EU leaders last week delayed a deadline for the charter to be ratified, prompting a series of countries to announce postponement of plans to hold their own referendums.
