Kuehlungsborn, Germany — Adjourning a meeting featuring some surprises and a less contentious tone than many expected, the leaders of the world's richest industrial nations pledged Friday to commit $60 billion for treatment of AIDS and other diseases in the developing world.

The pledge, which is to extend over an unspecified number of years, includes aid already promised by the Group of 8 leaders, and a fresh commitment by the United States, which is contributing half the total.

“We are aware of our obligations,” Chancellor Angela Merkel, the host of the meeting, declared after a session with five African leaders.

The $60 billion pledge allowed the leaders to part on a unified note, after two days of discussing divisive issues like climate change, the future of Kosovo and the growing gulf between Russia and the West. But the announcement on Friday was condemned as inadequate by aid groups.

Health groups were chagrined by the communique, which many felt was a “huge step backward,” said Marcel van Soest, executive director of the World AIDS Campaign, an umbrella group based in the Netherlands. He said the world's richest countries had failed even to live up to the commitments they made at a Group of 8 meeting in Scotland in 2005.

“All the good first steps, all the hope of 2005, seemed to go down the drain today,” he said.

Outside the heavily fortified meeting site in the resort of Heiligendamm, crowds of protesters also dispersed peacefully, after two days of blockades and clashes with the police.

Critics said the commitment on Third World disease would fall far short of what was needed to combat AIDS, malaria or tuberculosis. They particularly noted the lack of a timetable for the delivery of the money.

“Without a time frame, no one can be held accountable,” van Soest said.

In 2005, the leaders pledged to ensure universal access to HIV treatment by 2010. While the communique issued Friday still refers to “universal access,” it commits only to putting 5 million people into treatment “in the next few years,” said Tido von Schoen-Angerer, of Doctors Without Borders.

Moreover, he noted, the leaders vowed to strengthen patent protection for goods like medicines. This means the inexpensive generics that treat so many people in poor nations could become less available or more costly.

Merkel inherited her focus on Africa from Prime Minister Tony Blair, who championed it at the meeting in Scotland. But as with her effort to reach an agreement on climate change, Merkel faced resistance, notably from Japan, Italy and Canada.

She was helped by an unlikely combination of the rock star Bono, the former rocker and now concert promoter Bob Geldof, and President Bush. The musicians turned up in Heiligendamm to press the leaders.

Bono, who divided his time between the leaders and a concert for protesters in Rostock, the nearby Baltic city, said he was disappointed by the communique, saying it mixed references to treatment of diseases in Africa, and worldwide, to disguise the actual level of financing for Africa.

“I understand if they think rock stars can't add or subtract, or spell, or read,” he said at a news conference. “But some people around here can. This maze is designed to lose us. But we are not lost; the G-8 are lost.”

The Global Fund to Fight AIDS, Tuberculosis and Malaria, a multilateral group created to disburse the donations from the Group of 8 countries, said it was pushing for $6 billion to $8 billion a year for treatment — a goal that would require somewhat more than the cumulative $60 billion.

Still, Michel Kazatchkine, the executive director of the Global Fund, said in a statement, “This is a strong G-8 agreement that makes it possible to defeat the pandemics of AIDS, TB and malaria.”

The agreement on climate change, reached Thursday, has received better reviews, though critics note that the United States still refuses to accept mandatory reductions in greenhouse gas emissions.

On Friday, the group met with leaders from China and India to rally their support for deep emission reductions. Those fast-growing economies will account for the bulk of incremental emissions in coming years.

In a joint statement with Merkel, the leaders of the developing nations said, “We remain committed to contribute our fair share to tackle climate change.”

For Merkel, who staked much political capital on achieving a climate deal, the meeting was largely successful. Officials of several countries, as well as advocacy groups, praised her performance.

The subtext of this meeting may have been a changing of the guard. Blair, attending his final gathering, appeared nostalgic. President Nicolas Sarkozy of France, at his first, was very much the rookie, bounding ahead of the others and chatting on his cell phone, to the amusement of his peers.