U.S. President Barack Obama speaks at the end of the G8 summit in L'Aquila, Italy, on Friday. (Jason Reed/Reuters)

World leaders have laid a solid foundation on several key economic issues but a "full recovery is still a ways off," U.S. President Barack Obama said Friday as the G8 summit in Italy ended.

"The work we've done here reflects a recognition that the defining problems of our time will not be solved without collective action. No one corner of the globe can wall itself off from the challenges of the 21st century or the needs and aspirations of fellow nations," Obama told a news conference in L'Aquila.

"As we worked this week to find common ground, we have not solved all our problems, and we have not agreed on every point, but we've shown that it is possible to move forward and make real and unprecedented progress together."

The leaders of Algeria, Angola, Egypt, Ethiopia, Libya, Nigeria, Senegal and South Africa joined in the discussions Friday with their counterparts in the G8 — the Group of Seven countries (Canada, the United States, Britain, France, Germany, Italy, and Japan) and Russia.

Prime Minister Stephen Harper pointed out that Canada is one of the few countries that has lived up to its funding commitments to less-developed nations made at previous summits.

"Countries who have not been living up to their commitments are going to face increasing heat as we go forward," Harper said.

"When we as the G8 make commitments and we don't fulfill them, this undercuts the credibility of our process, and that is a serious problem."

Canadian Prime Minister Stephen Harper pauses during the news conference at the end of the G8 summit. (Chris Wattie/Reuters)

Musician and anti-poverty activist Bob Geldof told the CBC that the summit "looked like it had been a complete bust" until a breakthrough on food aid Friday morning largely driven by Obama.

Geldof confirmed Harper's contention that Canada has lived up to its G8 funding commitments and said the country is right to focus on accountability at next year's global meeting in Muskoka, Ont.

"When the show rolls into your neck of the woods next year, there is a deep credibility with the leaders, and I think it's quite right that Harper should say [to other countries], 'We've done it. Where is your stuff?'" Geldof said.

Among the goals agreed to over the three-day meeting to address economic, environmental and global security:

• $20 billion over the next three years to increase food production in developing countries and help the poor feed themselves. Some of the money represents previous aid pledges that G8 countries have lapsed on over the last four years.
• The G8 countries set the goal of reducing their greenhouse gas emissions by 80 per cent by 2050, with the global goal of a 50 per cent cut. They also pushed the G5 countries at the summit — Brazil, China, India, Mexico and South Africa — to commit to an agreement that an increase in global temperatures shouldn't exceed 2 C.
• Measures that help stop the spread of nuclear weapons by strengthening the non-proliferation treaty to encourage nations to meet arms control, disarmament and nonproliferation commitments.
• While the global economy is not stable enough to pull back the G8 nations' massive fiscal stimulus plans any time soon, they did commit to preparing exit strategies from the "unprecedented and concerted action" with the help of the International Monetary Fund.

Still tough on Iran: Obama

Obama rejected suggestions that the summit fell short of expectations by failing to call for new tough sanctions on Iran for its crackdown on democracy advocates after its disputed presidential election.

"What we wanted is exactly what we got — a statement of unity and strong condemnation," said Obama.

It was even more significant because it included Russia, "which doesn't make statements like that lightly," he said.

World leaders will reevaluate their position on Iran in September when the world's 20 major industrial and developing economies will meet, Obama said.

With files from The Associated Press