Leaders of poor nations warned their rich counterparts that if they want a world free of terrorism, they will need to pay for it. Drawing a direct link between poverty and violence, leaders at a U.N. summit said increased aid to the world's neediest is more urgent than ever in the post-Sept. 11 world. 

The leaders at the U.N. International Conference on Financing for Development, who have been discussing ways to narrow the gap between the haves and the have-nots, warned that the world's security depends on bringing relief to the desperately poor. 

"In the wake of Sept. 11, we will forcefully demand that development, peace and security are inseparable," said Han Seung-soo, president of the U.N. General Assembly. He said the world's poorest areas are "the breeding ground for violence and despair." 

Peruvian President Alejandro Toledo, looking weary hours after a car bomb killed nine people in his country's capital, also linked poverty to violence. 

"To speak of development is to speak also of a strong and determined fight against terrorism," he said before returning to Lima. 

President Bush arrived in Monterrey on Thursday and was scheduled to address the summit Friday morning before the leaders — some 50 in all — approve a consensus that urges rich nations to increase development aid and poor nations to use the funds more efficiently. 

The leaders also were scheduled to hold a private retreat at an art museum in this modern, industrialized city of northern Mexico. 

While both the United States and Europe have promised billions of dollars more in aid in coming years, their pledges still fall far short of the $100 billion a year the United Nations has said is needed to halve poverty by 2015. 

Cuban President Fidel Castro attacked rich nations for demanding that their poor counterparts meet conditions, such as fighting corruption, to receive aid. 

"You can't blame this tragedy on the poor countries. It wasn't they who conquered and looted entire continents for centuries, nor did they establish colonialism, nor did they reintroduce slavery, nor did they create modern imperialism," he said. "They were its victims." 

Dressed in military fatigues and black running shoes, Castro compared the international financial system to "a gigantic casino." 

Castro left the conference shortly after his speech — and hours before the arrival of President Bush — citing "a special situation created by my participation in this summit." 

He didn't elaborate, but Ricardo Alarcon, president of Cuba's National Assembly, later told The Associated Press that Castro left because of "a situation that for a self-respecting country like Cuba, was unacceptable," but wouldn't elaborate. 

"In the final analysis it is a problem with the United States," Alarcon said. "That doesn't mean that someone from the United States talked to us or asked us to do something." 

According to a U.S. official who spoke on condition of anonymity, the U.S. delegation had been instructed to leave the designated U.S. seat when it was Castro's turn to speak, and they did. It was unclear whether that was what had offended Castro. 

Most participants agreed the biggest achievement of the summit was getting international leaders, business leaders and activists together to talk about combatting poverty. 

Anti-globalization protesters, who have held small marches throughout the week, held their largest demonstration Thursday. About 2,000 protesters massed in front of a police barricade a few blocks from the conference, where they burned an effigy of Uncle Sam and hurled dead goats, which they said died from toxic waste from a nearby factory, over the barricades. 

But even international finance chiefs addressed some of the issues the protesters have clamored about for years. 

"Poverty in all its forms is the greatest single threat to peace, democracy, human rights and the environment," World Trade Organization Director-General Mike Moore said. "It is a time-bomb against the heart of liberty. But it can be conquered and we have the tools in our hands to do so, if only we have the courage and focus to make proper use of them." 

Officials said the world's misery affects all. 

"We live in one world, not two," said U.N. Secretary-General Kofi Annan. "No one in this world can feel comfortable, or safe, while so many are suffering and deprived."