L’AQUILA, Italy (AP) — President Barack Obama joined fellow world leaders in Italy Wednesday for talks on threats to global security and stability at a summit where climate change, a continuing global economic crisis, nuclear proliferation and world hunger took top billing.

The G-8 meetings may lack the intrigue of Obama’s sit-downs earlier in the week with Russia’s top leaders, or the emotion of the reception the first black American president surely will get in Ghana Saturday. But they won’t lack for ambition, on the surface at least, as the world’s most powerful officials discuss the problems threatening the planet.

Obama and the leaders of seven other industrialized nations had meetings set in the picturesque town of L’Aquila, northeast of Rome, before they were to widen their circle to include fast-growing countries like China and India, and struggling nations from Africa. In large and small groups, the talks will involve trade, Iran’s nuclear ambitions, food security and other issues.

Obama, accompanied by his wife Michelle, went immediately into a meeting Wednesday morning with Italian President Giorgio Napolitano after arriving at the stately Quirinale Palace in Rome, meeting his host in a spectacular setting that included a large room with a soaring ceiling, gilded walls and doors and huge chandeliers.

Emerging from the meeting with Napolitano, Obama said he was looking forward to the G-8 talks and praised his Italian hosts for being “such good friends” of the United States over the years.

He said the two countries among other things “are working hand in hand in places like Afghanistan to ensure that we’re isolating extremists and strengthening the forces of moderation around the world.” Obama also said he and Napolitano agreed that efforts must continue in the area of “raising standards on financial institutions” to protect against future global economic meltdowns.

He also said that it is crucial that world leaders work to ensure that Iran and North Korea don’t “take a path” that would widen the arms race on the Korean peninsula and in the Mideast.

Topping the list of G-8 discussions are possible ways to slow the release of greenhouse gases linked to global warming.

Security is heavy in L’Aquila, which was ravaged by an earthquake on April 6. Officials have prepared emergency airlifts of the world leaders in case another strong tremor hits.

Many foreign leaders want the United States to embrace a target of limiting the rise in average planetary temperatures to 3.6 degrees (2 degrees Celsius) higher than they were in 1900, before widespread industrialization. Scientists say an increase beyond that could trigger dangerous rises in sea level and other dire problems.

White House Press Secretary Robert Gibbs declined Wednesday to say whether the administration would endorse the goal. But he suggested that the administration is putting its political emphasis on what it can accomplish back home with Congress, not with the Group of Eight (or G-8) at an international summit.

“I would say that I think our biggest contribution to this is the steps that were taken by the House,” Gibbs said, referring to legislation requiring reductions in greenhouse gases.

Setting goals and achieving them, of course, are different things, and G-8 meetings often are known more for high-minded roundtables and photo opportunities than for concrete results. Even before Obama left Washington, his aides tamped down expectations of breakthroughs at L’Aquila.

Presidential adviser Mike Froman told reporters that it’s not quite time for industrialized nations to pull the plug on economic stimulus efforts.

World leaders gathered here will seek a balance between continuing to stimulate sluggish economies and looking for exit strategies, he said. Froman also said there is still uncertainty and risk in the global economy and said it’s important to return to fiscal sustainability, which would not include government stimulus efforts. Some G-8 leaders have urged Obama to support an end to stimulus efforts soon.

Obama made a major speech in Moscow after jointly declaring with Soviet President Dmtry Medvedev a desire to find agreement by year’s end on a treaty to slash U.S. and Russian nuclear stockpiles by a third. Barring a breakthrough on climate change, or perhaps new sanctions against Iran, the emotional highlight of Obama’s Italy trip may be his audience Friday with Pope Benedict XVI at the Vatican.

The summit here involves an ever-growing number of nations beyond the G-8, whose members are the United States, Canada, Britain, France, Germany, Italy, Russia and Japan.
Various meetings will include representatives of Egypt, Turkey, Mexico and several other nations.

Steven Schrage, a business scholar at the Washington-based Center for Strategic and International Studies, said the G-8 sometimes struggles for a clear-cut identity and purpose.

The best title for this week’s meeting, he said, might be “G-question mark.”

“It’s going to start with the traditional G-8,” Schrage said, “but then rapidly accelerate into a kind of crescendo of different nations, going up to 39 nations that will span much of the globe.”

Associated Press writers Alessandra Rizzo in L’Aquila and Ben Feller in Rome contributed to this report.

Photo: AP Photo/Philippe Wojazer, Pool. From left, Japanese Prime Minister Taro Aso, Canadian Prime Minister Stephen Harper , U.S. President Barack Obama and French President Nicolas Sarkozy stand for a group photo of world leaders at the G8 summit in L’Aquila, Italy on Wednesday, July 8.