Spurred to action by last week's bombing of U.N. headquarters in Iraq, the Security Council on Tuesday unanimously approved a resolution aimed at protecting U.N. staff and humanitarian workers after the United States agreed to a compromise.

The resolution had languished since late April because of U.S. opposition, but surged into the spotlight after the attack which killed 23 people, including 19 U.N. staff members, and injured more than 160.

It said deliberate attacks on U.N. and other humanitarian workers in armed conflicts are a war crime -- and demands the prosecution of anyone who tries to harm them.

Secretary-General Kofi Annan (search) said that regrettably, in recent years the United Nations had not lived up to its obligation to protect humanitarian workers and U.N. personnel and attacks against them "have increased alarmingly."

It is not acceptable, he said, to continue to let these "servants of humanity" be soft targets, and the perpetrators must be sent a message that "impunity for those who commit such unpardonable crimes cannot stand."

Speaking immediately before the vote, Annan called for unanimity in the council, saying there was "no issue about which I feel more strongly ... than the safety of those brave men and women" serving in danger zones.

During intense negotiations, Mexico and the other supporters of the resolution agreed to drop a reference to the International Criminal Court, which the United States vehemently opposes, and reached agreement with Washington on defining what constitutes a war crime against humanitarian personnel.

That cleared the way for the 15-0 vote.

The United States objected to a statement in the original draft declaring that attacks against humanitarian personnel and peacekeepers are considered a war crime by the International Criminal Court. The Bush administration fears the court could launch frivolous prosecutions against American peacekeepers and officials.

But the 90 countries that have ratified the 1998 Rome Treaty creating the world's first permanent war crimes tribunal counter that it contains enough safeguards to prevent any frivolous prosecutions.

The 15 Security Council nations agreed on language emphasizing "that there are existing prohibitions under international law" against deliberate attacks against humanitarian or peacekeeping personnel "which in situations of armed conflicts constitute war crimes."

Mexico and the other co-sponsors of the resolution -- France, Russia, Germany, Bulgaria and Syria -- insisted that the resolution must have no ambiguity that attacks on humanitarian personnel constitute a war crime.

Mexico's U.N. Ambassador Adolfo Aguilar Zinser (search) said the supporters regret that the court isn't mentioned. But Richard Dicker, head of the international justice program at Human Rights Watch, said its absence "doesn't change the practical impact of this resolution."

"The resolution makes prosecution of those accused of attacks on humanitarian aid workers more likely before the International Criminal Court and other courts," he said.

The resolution strongly condemns all forms of violence against humanitarian workers. It urges states to punish such crimes and to pass laws making violence against humanitarian workers a criminal offense.