LONDON — Spain's newly elected prime minister pledged Monday to bring his peacekeeping troops home from Iraq by June 30. All other governments helping rebuild Iraq said they would stay the course, but there were signs of nervousness after the Madrid bombings and the Spanish government's defeat at the polls.

Socialist leader Jose Luis Rodriguez Zapatero's remarks came as Spanish police investigated whether Thursday's coordinated bombings were carried out by Islamic extremists — possibly al-Qaida — intent on punishing Spain for its support for the U.S.-led war. The blasts killed 200 people and wounded about 1,600.

Britain, America's closest ally, insisted the coalition must remain committed to bringing stability and democracy to Iraq. So far, no significant opposition party has called for a withdrawal of Britain's 8,220 troops.

Poland, which leads a multinational force in southern Iraq, said a pullout of its 2,500 troops would hand a victory to terrorists. Prime Minister Leszek Miller pledged to stay with the peacekeeping mission despite pressure from opposition lawmakers.

"It would amount to an admission that the terrorists are right and that they are stronger than the whole civilized world," Miller said.

The European Union, meanwhile, announced it would hold high-level security talks Friday in Brussels, Belgium, to assess additional anti-terrorism measures, including a continentwide intelligence service and a European arrest warrant.

Last October, Poland and Spain, also a U.S. ally in Iraq, were named as possible targets on a taped message attributed to al-Qaida leader Osama bin Laden.

"We reserve the right to respond at the appropriate time and place against all the countries participating in this unjust war (in Iraq), particularly Britain, Spain, Australia, Poland, Japan and Italy," said the voice on the tape, broadcast on Al-Jazeera.

But British Foreign Secretary Jack Straw said Monday that all countries, not just those who supported the campaign to topple Saddam Hussein, were the targets of terrorists.

"We are under a threat from Islamic extremism, and so is almost every other country in the world," Straw told British Broadcasting Corp. radio. "No one should believe that somehow if you say 'I opposed the military action in Iraq,' that this makes you safer or exempts you as a potential victim."

Spanish voters on Sunday ousted the conservative government of Jose Maria Aznar, some of them accusing his government of provoking the attacks by backing President Bush.

His successor, Zapatero, described the war as an "error" and said Monday he would bring the 1,300 Spanish peacekeepers home by June 30 unless the United Nations takes control in Iraq.

The U.N. Security Council has authorized the current multinational force in which Spain is participating. But there has been no talk of turning that force, which is led by the United States, into a U.N.-controlled peacekeeping force.

The Polish ambassador to NATO, Jerzy Nowak, told The Associated Press he was deeply concerned about a possible Spanish withdrawal, adding it would leave a "terrible loophole" in the multinational force.

In Bulgaria, which lost four citizens in the Madrid bombings, the government insisted it would not pull its 500-member infantry battalion from the southern Iraqi city of Karbala.

"The only policy we can conduct is to fight international terrorism," Bulgarian Foreign Minister Solomon Pasi said.

In Japan, Prime Minister Junichiro Koizumi said he foresaw no change in plans to deploy 1,000 Japanese military personnel in the Persian Gulf region to assist in Iraq's reconstruction.

"Japan's (political) situation is different from Spain's," Kyodo News agency quoted him as saying.

Koizumi faces intense pressure from opponents who fear Tokyo's involvement could make Japan a terror target. Last November, an alleged al-Qaida operative threatened to attack Tokyo if it sent troops to Iraq.

Roman Giertych, the head of the Polish Families' League, a far-right Catholic party, said he wants a referendum to determine whether Poland remains with the U.S.-led coalition.

"The whole nation is in danger — not the government itself — and people should decide if our troops should stay there or not," Giertych told AP.

The Czech government said it had no plans to withdraw its 150 military police from Iraq.

Ukraine, which has contributed some 1,650 troops to the Polish-led multinational contingent, is also not considering a withdrawal, said Kostiantyn Khivrenko, Defense Ministry spokesman.

Irish Prime Minister Bertie Ahern said proposals to be discussed at the EU meeting would also include a "solidarity clause" committing nations to help each other in response to terror attacks, as well as appointment of a security coordinator to oversee counterterrorism measures, improved intelligence sharing and closer cooperation with outside nations to combat terrorism.