EC President Jose Manuel Barroso delivered a State of the Union address to members of the European Parliament during a plenary session in Strasbourg, France.
He said the European economy has "fought back" from the international financial crisis that spilled out of the U.S. economy five years ago.
"We suffered the crisis together," he said in his prepared remarks Wednesday. "We realized we had to fight it together."
Eurostat, the European Commission's statistics agency, said last week the economy in the 28-member European Union grew 0.4 percent April through June, a slight increase from the previous estimate.
British Prime Minister David Cameron in January said frustration with EU policies has grown and the British would "have their say" on EU membership in a 2015 referendum. Last week, European leaders said they needed a united defense policy to ensure security for members of the bloc.
Barroso said members need a Europe that's strong, united and open. The debate should be focused on improvements rather than abandonment.
"If you don't like Europe as it is, improve it," he said. "Find ways to make it stronger, internally and internationally, and you will have in me the firmest of supporters."