US presidential candidate Mitt Romney has been forced to backtrack on comments in which he appeared to question Britain's readiness to host the Olympic Games as he visited London for talks with David Cameron.
Mr Romney told an American TV network on Wednesday that there were "disconcerting" signs around the Games, and it was "hard to know just how well it will turn out".
But after his discussions with the Prime Minister in 10 Downing Street, the Republican presidential hopeful was full of praise for London's preparations.
"I am very delighted with the prospects of a highly successful Olympic Games," said Mr Romney. "What I have seen shows imagination and forethought and a lot of organisation. I expect the Games to be highly successful."
Speaking to NBC News, Mr Romney had said: "It's hard to know just how well it will turn out. There are a few things that were disconcerting. The stories about the private security firm not having enough people, the supposed strike of the immigration and customs officials - that obviously is not something which is encouraging."
And he questioned British enthusiasm for the Olympics, asking: "Do they come together and celebrate the Olympic moment? And that's something which we only find out once the Games actually begin."
Mr Cameron faced questions about Mr Romney's comments at an eve-of-Games press conference with organiser Sebastian Coe at the Olympic Park.
He stopped short of criticising his US guest, telling reporters: "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."
But some observers thought the PM may be drawing a pointed contrast with Mr Romney's own experience as chief executive of the Salt Lake City Winter Olympics in 2002 when he said: "We are holding an Olympic Games in one of the busiest, most active, bustling cities anywhere in the world. Of course it's easier if you hold an Olympic Games in the middle of nowhere."
Mr Romney's visit to London also took in talks with Chancellor George Osborne, Deputy Prime Minister Nick Clegg, Labour leader Ed Miliband, former PM Tony Blair and MI6 chief Sir John Sawers.