The event will discuss issues, including the eurozone crisis, Iran nuclear standoff, Syria, global energy and food security, among others.
Washington: Leaders of the world's eight most powerful economies are set to discuss the eurozone crisis, apart from key international issues like Iran, Syria, Myanmar and North Korea at their crucial summit at Camp David in the US.
President Barack Obama, who welcomed the G-8 leaders at Camp David outside Washington, said that the European situation held "extraordinary" importance for the US.
He emphasised the need for G-8 to discuss "a responsible approach to fiscal consolidation that is coupled with a strong growth agenda."
Following a dinner among the leaders at the presidential retreat at Camp David last night, a top Obama administration official said the leaders believe there is a sense of urgency on the issue of Iran and that the onus is on the Iranians to take concrete steps to demonstrate that their nuclear programme is peaceful.
They wanted to make sure the Iranians understand that they need to take concrete steps, the official said.
The G-8 comprising the US, Japan, Britain, Germany, France, Italy, Canada and Russia underscored the need for a dual-track process, while also moving forward with the pressure they put on Iran.
Russian President Vladimir Putin is not attending the summit. Instead, he would be represented by his predecessor and Prime Minister Dmitry Medvedev.
During the dinner which took place around a round table, the leaders also discussed Syria, North Korea, Myanmar and the importance of including women in the political process.
On Syria, they discussed the Kofi Annan plan, and focussed on need for full implementation of it.
The G-8 leaders talked about the need to move towards political transition in Syria, the official said, adding that there was no disagreement on it.
Exactly what the nature of the transition is will be worked through in coming days.
The Russian Prime Minister did not dispute the need for some type of political process on the country that would be responsive to the Syrian people.
On North Korea, Medvedev went out of his way to say they are lockstep with the US in opposing the missile launch, the official said.
The G-8 leaders agreed that North Korea would be further isolated if they went ahead with their missile launch.
On Myanmar, President Barack Obama talked about easing of sanctions, and also his nomination of the US Ambassador to the country after 22 years.
Transition is promising but not complete, he noted.
Earlier, Obama welcomed the leaders of G-8 countries, which is the largest ever gathering of foreign leaders at Camp David -- at the entrance of the Laurel Cabin, a large green lodge under a canopy of trees.
Greeting the Italian Prime Minister Mario Monti, Obama apologised for the long flight and said, "Hopefully we'll get some stuff done."
British Prime Minister David Cameron liked the setting of Camp David and told Obama that this is a nice, peaceful spot.
Medvedev, wearing an electric-blue blue sport coat with jeans, joked: "This is my new place!" Each leader shook hand with the US President and walked inside for their working dinner.
Before turning in, Obama had a birthday cake delivered for the Japanese Prime Minister Yoshihiko Noda, whose birthday is tomorrow.
It was chocolate cake, according to a source familiar with the dessert.