Leaders from the Group of Seven advanced economies will examine potential risks to the global economy when they gather this week for their summit in western Japan, government sources told Reuters.

While the global economy is not at a critical stage, uncertainty is rising, and the G7 leaders are expected to promote a combination of monetary, fiscal and structural policies to spur growth at their gathering, the sources, who were not authorized to speak to the media, said.

"Uncertainty is rising. We are going to [discuss] downside risks to the global economy," one of the two sources told Reuters on the condition of anonymity.

The G7 comprises Britain, Canada, France, Germany, Italy, Japan and the United States.

With Britain and Germany resisting calls for fiscal stimulus, Japanese Prime Minister Shinzo Abe is set to urge the G7 leaders to adopt a flexible fiscal policy, taking into account each country's own situation, the sources said.

The G7 leaders are also expected to reaffirm their previous commitment to stability in the foreign exchange market, they said.