The Philippines said Wednesday it had withdrawn some of its peacekeepers from Iraq and was coordinating a pullout, apparent efforts to meet the demand of kidnappers threatening to kill a captive Filipino truck driver.

A full withdrawal before its scheduled departure date by one of Washington's biggest backers in the war on terror would be a major blow to the unity of U.S.-led coalition in Iraq.

"The Foreign Affairs Ministry is coordinating the pullout of the humanitarian contingent with the Ministry of National Defense," a Philippines government statement said. "As of today, our head count is down from 51 to 43."

The government has been vague on many of its comments on the kidnapping and it wasn't immediately clear if the statement meant the such a withdrawal had already begun or if it would include all its troops.

There was no immediate U.S. comment to the latest announcement, but U.S. officials had earlier expressed displeasure that Manila was even considering caving in to the kidnappers' demand, a position echoed by Australia and Iraq's new interim government.

A deadline set by the Iraqi Islamic Army-Khaled bin Al-Waleed Corps (search) for the Philippines to meet the group's troop withdrawal demand expired early Tuesday, but negotiations continued in Iraq through intermediaries.

The insurgents had told President Gloria Macapagal Arroyo (search) that Angelo dela Cruz (search), a poor father of eight, already had been moved to the place he would be killed if she didn't change her mind.

Iraqi militants have repeatedly used terrorist attacks to try to force governments to withdraw from the U.S.-led occupation force.

In March, a series of terrorist bombings on commuter trains in Madrid shortly before national elections was believed to have contributed to a victory by the socialists, who had campaigned on a platform of withdrawing Spanish troops from Iraq. New Prime Minister Jose Luis Rodriguez Zapatero pulled out the troops soon after taking office.

Militants also tried to pressure South Korea by kidnapping one of its citizens in Iraq and demanding that Seoul drop plans to deploy 3,000 troops beginning in August. South Korea refused, and the captive was beheaded last month.

The hostage crisis put the Philippines president squarely between domestic concerns and her previously strong commitment to the United States, the Philippines' former colonial power.

With a terror threat of its own, the Philippines has been relying on Washington to beef up its poorly armed military to battle Al Qaeda-linked groups in the restive Muslim south. There had been concerns that local Muslim militants, such as the Abu Sayyaf group (search), may be encouraged once the government has agreed to meet the demand of the Iraqi captors.

The timing was also particularly bad, with political wounds still fresh from a bitter election.

The Philippine government had imposed a news blackout on the crisis Monday.