The EU will be more effective and dynamic and bring the Europeans closer together and gain more popularity because of the Lisbon Treaty which come into effect on Dec. 1, said Zapatero, whose country took over the six-month rotating presidency from Sweden on Friday.
"Nevertheless, Europe has been in need of more far-reaching changes for some time," he said, adding that "we must make Europe(an) increasingly important player on the international stage."
The Lisbon treaty has given birth to a new leadership structure for the 27-nation bloc, including its first full-time president and a new foreign policy chief. The two posts were taken by Belgium's Herman Van Rompuy and Britain's Catherine Ashton respectively.
As permanent president, Rompuy promised on Friday to work "hand in hand" with the Spanish rotating presidency for the first six months of his term.
Jerzy Buzek, president of the European Parliament, said the coming six months from Jan. 1 are "extremely important" for the implementation of the Lisbon Treaty.