A US official on Monday disputed a French source's account that President Barack Obama had told his allies at a G7 summit that the strong dollar posed a "problem".

Amid mounting fears over the Greek debt turmoil's impact on the fragile global economy, a US official said: "The President did not state that the strong dollar was a problem.

"He made a point that he has made previously a number of times: that global demand is too weak and that G7 countries need to use all policy instruments, including fiscal policy as well as structural reforms and monetary policy, to promote growth."