One day after formally taking office and hours after most of his cabinet was sworn in, Prime Minister Zapatero announced on Spanish television Sunday that he has ordered his new defense Minister, José Bono, to take the necessary measures to withdraw Spanish troops deployed in Iraq in the shortest time and with the greatest security possible.

After his Socialist Party's election last month, Mr. Zapatero said he would pull Spanish troops from Iraq unless they come under U.N. command by June 30. In his remarks Sunday, the prime minister explained why he was acting more quickly. "He said that on the basis of information gathered over the past several weeks, there was no indication that the U.N. would adopt a resolution meeting the conditions he had set for the continued deployment of Spanish troops in Iraq," he said.

However, Mr. Zapatero, who said he would appear before parliament on Monday to explain his decision, was careful to underline that Spain would continue to be a faithful member of its alliances and would meet its commitments in carrying out international missions of peace and security.

The leader of the main opposition Popular Party, Mariano Rajoy, who has succeeded former Prime Minister José María Aznar, said the decision was taken hastily and without consulting parliament at a moment when efforts were being made to reach an agreement on a resolution in the United Nations. He also said it showed a lack of solidarity with allied nations which also had forces in Iraq.

Though polls showed the overwhelming majority of Spaniards were opposed to the U.S.-led war in Iraq, the Aznar government sent troops there last year after the invasion on an expressly humanitarian mission to help stabilize the country.

Mr. Zapatero was an incessant critic of Mr. Aznar's steadfast support of President Bush's policies toward Iraq. With the withdrawal of Spanish troops from Iraq he has fulfilled a major campaign pledge.