G8 summit targets growth and security.

The summit of the G8 group of major world economies is under way at Camp David, near Washington, with Europe's debt crisis expected to dominate.

US President Barack Obama said all the G8 nations were "absolutely committed" to the goals of growth, stability and fiscal consolidation.

Germany, which backs austerity, is under pressure from the US and France for stimulus measures, analysts say.

Greece's possible exit from the eurozone is high on the agenda.

The leaders of the G8 nations - the US, Germany, the UK, France, Italy, Japan, Canada and Russia - have now begun their talks at the Camp David presidential retreat, in Maryland.

UK Prime Minister David Cameron said a sense of urgency was needed to tackle the eurozone crisis. He called for strong banks and deficit reduction.