From left to right: Japanese Prime Minister Taro Aso, U.S. President Barack Obama, French President Nicolas Sarkozy, Canadian Prime Minister Stephen Harper, Italian Prime Minister Silvio Berlusconi and Russian President Dmitry Medvedev arrive for a group photograph at the G8 summit in L'Aquila, Italy on Wednesday. (Jason Reed/Reuters)

Prime Minister Stephen Harper urged fellow Group of Eight leaders on Wednesday to be patient with the faltering global economy and not craft more stimulus packages until the current ones have had a chance to work.

"My own thought is before there's talk of additional stimulus, I would urge all leaders to focus first on making sure the stimulus that's been announced gets delivered," Harper said Wednesday, the first day of the G8 summit in L'Aquila, Italy.

The economy took centre stage at the meeting, with the eight leaders releasing a draft statement that notes that the global economy is not stable enough to pull back the nations' massive fiscal stimulus plans any time soon. Canada alone has pledged $46 billion over a two-year period.

Prime Minister Stephen Harper at the opening of a round table session at the G8 summit in L'Aquila, Italy on Wednesday. (Chris Wattie/Reuters)

However, the leaders from Britain, Canada, France, Germany, Italy, Japan, Russia and the United States did commit to preparing exit strategies from the "unprecedented and concerted action" with the help of the International Monetary Fund, according to the statement.

"We will take, individually and collectively, the necessary steps to return the global economy to a strong, stable and sustainable growth path," the leaders' draft communiqué said.

The measures include continuing their stimulus packages while keeping inflation under control, and ensuring banks have enough cash to keep lending.

Differences among the countries, however, were already apparent.

While Harper is stressing there is no immediate need for additional global financial packages and Germany is pushing for spending restraint, other major economies like Britain, Japan and the United States have not ruled out spending more.

Iran, North Korea top of agenda

Group of Eight leaders also spoke out on Iran on Wednesday, saying in a joint statement that they are "seriously concerned" about Iran's violent crackdown on protesters in the aftermath of last month's disputed election.

The G8 leaders added that they remain committed to seeking a diplomatic solution to Iran's contentious nuclear program. The leaders said they welcomed U.S. President Barack Obama's willingness to engage in direct talks with Tehran.

"We sincerely hope that Iran will seize this opportunity to give diplomacy a chance to find a negotiated solution to the nuclear issue," the statement said.

Prior to the talks, Canadian officials said Harper would be pushing for a "comprehensive response" to Iran's nuclear push.

In a series of declarations on global security threats, the G8 also condemned "in the strongest terms" North Korea's nuclear tests and ballistic missile launches in defiance of UN resolutions.

And they urged Afghanistan to ensure credible elections next month.

Meanwhile, China's President Hu Jintao, who had planned to take part in a G8 meeting with major developing countries, cut short his trip to Europe to return home amid ethnic clashes in China's western Xinjiang province.

'Historic' climate change agreement

Masked protesters chain themselves to a G8 sign ahead of Wednesday's summit meetings. (Bullit Marquez/Associated Press)

The leaders agreed Wednesday that an increase in global temperatures shouldn't exceed 2 degrees Celsius. Many scientists say an increase beyond that could trigger dangerous rises in sea level and other dire problems.

Harper called it a "much stronger statement" than last year's G8 climate change communique while British Prime Minister Gordon Brown called it "historic" and German Chancellor Angela Merkel said it was a "clear step forward."

Thursday, a wider group of nations will discuss the climate change goal, talks that Harper suggested would be challenging. Representatives from about 30 countries beyond the G8, including Egypt, Turkey and Mexico, will also be participating in the summit.

"The emerging economies will be hit as hard if not harder by climate change as anyone, so it's important for them to realize the necessity of making commitments," Harper said.

Climate change experts applauded the G8.

"Until today, Canada had never taken a position on what level of global warming is too dangerous," said Clare Demerse of the Pembina Institute.

"Thanks to pressure from its G8 peers, Canada has now accepted what scientists and leading countries have been saying for years."

'Your tears were our tears'

Italian Prime Minister Silvio Berlusconi, who is hosting the summit, moved the G8 to L'Aquila after the Abruzzo region, west of Rome, was devastated by an earthquake in April that killed 300 people and left more than 60,000 homeless.

Several of the G8 leaders toured an area of L'Aquila destroyed by the earthquake. The city still feels aftershocks from the quake, and many residents are living in tents. Officials have prepared emergency airlifts of the world leaders in case another strong tremor hits.

Harper announced that Canada will contribute $5 million to the building of a youth centre, including a gymnasium and library, at the city's university.

"Your tears were our tears," Harper said at a small ceremony held with the mayor of L'Aquila.

With files from The Associated Press and The Canadian Press