Implementing Lisbon Treaty and tackling bloc's economic woes to be focus of presidency.
Spain has assumed the rotating presidency of the European Union, the first under a new leadership structure for the bloc which includes its first full-time president and a new foreign policy supremo.
The positions, occupied respectively by Belgium's Herman Van Rompuy and Britain's Catherine Ashton, were created under the Lisbon Treaty which came into effect on December 1, during the final weeks of Sweden's six-month term at the helm of the EU.
Madrid has set as the priorities for its presidency a smooth implementation of the treaty and tackling the continent's economic problems.
The treaty aims to streamline decision-making in the 27-nation bloc but critics argue the new system is no less complex and multi-layered than the previous one, with too much scope for overlapping roles.
In a message posted on the official website of the Spanish presidency, Jose Luis Rodriguez Zapatero, Spain's prime minister, said the main challenge will be to provide Europe with an economy that is "more productive, innovative and more sustainable".
Zapatero said that he was "convinced" that the Lisbon Treaty will make Europe "more efficient and dynamic" and contribute to "make Europeans more united".
One of the aims of the EU's new leadership structure is to give Europe a greater voice on the world stage in talks with major powers like China and the United States.
Under the Lisbon Treaty, Rompuy, Ashton and Jose Manuel Barroso, the European Commission president, are intended to be the EU's public face.
But Spain will still chair important EU ministerial meetings on the economy, the environment and energy during the presidency as well as host several summits.
The summits include one between the bloc and Washington in May which Barack Obama, the US president, is expected to attend.
Jerzy Buzek, president of the European Parliament, said: "The coming six months are extremely important for the implementation of the Lisbon Treaty.
"The Spanish presidency will shape the new model of co-operation between EU institutions and member states under the Lisbon Treaty."
During the Spanish presidency the EU needs to agree on a replacement for the bloc's long-term growth strategy known as the Lisbon Agenda which was supposed to make it the world's most competitive economy by 2010.
A new 10-year growth strategy, dubbed the "2020 strategy," is likely to be adopted in March during a summit of EU leaders.
The unemployment rate in the entire EU rose to 9.3 per cent in October, representing 22.5 million people, from 7.3 per cent during the same time last year, according to EU statistic agency Eurostat.
The jobless rate in individual member states varies from lows of 3.7 per cent in the Netherlands and 4.7 per cent in Austria to highs of 19.3 percent in Spain and 20.9 per cent in Latvia.
As fireworks greeted the New Year, Spain raised the level of its anti-terrorist alert, fearing attacks by Eta, the armed Basque separatist group, during its EU presidency.