Asked about US Republican presidential candidate Mitt Romney's comments questioning Britain's readiness to host the Olympics, Mr Cameron said: "Of course, this is a time of some economic difficulty for the UK, everybody knows that.
"But look at what we're capable of achieving as a nation, even at a difficult economic time. Look behind me at this extraordinary Olympic Park built from nothing in seven years. Let me pay tribute by the way to the government that came before mine and the one before that - all played a role in this.
"In terms of the country coming together, I think the torch relay really demonstrates that this is not a London Games, this is not an England Games, this is a United Kingdom Games.
"I think we'll show the whole world not just that we've come together as a United Kingdom, but also we're extremely good at welcoming people from across the world."
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