Spanish Prime Minister Jose Luis Rodriguez Zapatero was to fly to Washington on Monday to meet President Barack Obama, a visit that comes after years of strained relations with George W. Bush's administration over the Iraq war.

The meeting Tuesday is the first official invitation of a Spanish premier to the White House since Zapatero's 2004 announcement that he was withdrawing his country's troops from Iraq, arguing that the U.S.-led invasion was illegal. The war was hugely unpopular in Spain, and Zapatero made it an electoral promise to pull out.

That move infuriated the Bush administration, which had close relations with Zapatero's conservative predecessor, Jose Maria Aznar. For the next four years, there was little or no contact between the U.S. and Spanish leaders.

Zapatero's Socialist government welcomed Obama's election last year as an opportunity to come back in from the cold. Tuesday's visit is seen as demonstrating a new understanding in bilateral relations.

"The Spanish government values positively the new foreign policy vision of the Obama administration," said Milagros Hernando, a top aide to Zapatero.

Developments in the Middle East are likely to be high on the agenda of talks between the two. After his Washington visit, Zapatero will fly to the Middle East to meet government leaders in Syria, Israel, the Palestinian territories and Lebanon.

The Spanish government says Spain will also take the opportunity to inform Washington of its decision to take no more than three Guantanamo prisoners.

Cooperation on combating climate change in the run up to the meeting of world leaders in Copenhagen in December is also likely to be discussed. Afghanistan is certain to be another topic.

Last month, Spain agreed to boost its troop contingent in Afghanistan by 220 soldiers, raising the total to about 1,000 following U.S. calls for more help from its allies.

Zapatero has never hidden his admiration for Obama and on Friday took the opportunity again to praise the U.S. leader for winning a Nobel.

"I feel great admiration for President Obama and the concession of the Nobel Peace Prize is due to the way that he, from the presidency of the world's leading power, is handling international relations with that permanent offer of dialogue and understanding, openness to peoples, nations and flags."

The two have met several times at international meetings over the past year.

In Prague this spring, Obama praised Zapatero saying, "I am glad to call him a friend and I welcome our opportunity to cooperate on a whole host of issues in the years to come."

Policy-wise they both are firm supporters of promoting renewable energies and fomenting dialogue with the Muslim world.

On a personal level, the two are seen to have a a lot in common, both having being born on Aug. 4 — Zapatero in 1960, Obama in 1961 — they are keen basketball fans and both are married with two daughters.