The United States congratulated the European Union on the signing of its constitution earlier Friday in Rome, hoping the treaty will enhance trans-Atlantic relations. "I do want to congratulate the 25 European member states on the signing of the European Union's Constitutional Treaty," State Department spokesman Richard Boucher said. "We hope the treaty, if and when ratified, will serve to enhance the outstanding working relationship that exists between the United States and the European Union." European Union leaders signed the constitution that lays the foundation for the recently expanded 25-nation bloc. The new document is designed to make the enlarged E.U. more efficient, democratic internationally effective. The signing comes after years of haggling over the constitution's new provisions for improved decision-making, the composition of the European Commission and creation of the post of E.U. foreign minister. E.U. governments have two years to ratify the document through either public referendums or national parliaments.