John McCain, the influential US senator, on Friday gave voice to resistance in the Republican party to the use of force in Iran, signalling that the US had no appetite to fight ?two wars?.

Force should not be ruled out as a last resort against the country's suspected nuclear facilities, he said, but cautioned: ?I do not think it would be successful. There is no guarantee we would get all these facilities. If you have a strike and leave them with nuclear capability, you have got a hell of a challenge on your hands.?