World leaders expressed their commitment to fight global terrorism Monday at a special counter-terrorism conference in New York.

Secretary General Kofi Annan opened the day-long conference, called "Fighting Terrorism for Humanity," just hours after a car bomb exploded near the United Nations Baghdad headquarters.

He told the the world leaders, who are in New York for the U.N. General Assembly opening session, that military force alone cannot defeat terrorism.

"To fight terrorism, we must not only fight terrorists. We have to win hearts and minds. To do this, we should act to resolve political disputes, articulate and work towards a vision of peace and development and promote human rights," he said.

The goal of the summit is to examine the roots of terrorism. To foster discussion, the conference's organizers, the Norwegian government and the International Peace Academy, distributed a report from a recent counter-terrorism conference in Oslo, Norway. It points to several factors that cause terrorism, including rapid modernization, discrimination, a culture of violence, and extremist ideologies, both religious and secular.

But the report also says that, contrary to a widely held belief, "there is only a weak and indirect relationship between poverty and terrorism."

Many of the heads of state at the New York conference did not agree on a definition of terrorism, particularly when it involves nationalist disputes such as the Israeli-Palestinian conflict and India and Pakistan over Kashmir.

Pakistani President Pervez Musharraf called on the international community to define terrorism. "Is it not ironic that even as we come to grips with the ravages of terrorism, we do not have a precise definition? Is it that political expediency dictates avoiding truth? We must have a clear, legal definition of terrorism. Terrorism has many forms, different motivations and diverse causes," he said.

Representing the United States, Senator Richard Lugar, chairman of the Senate Foreign Relations Committee, spoke of the danger posed by weapons of mass destruction.

Many of the leaders called for further international cooperation to combat terrorism two years after the September 11th, terrorist attacks.