"We are holding an Olympic Games in one of the busiest, most active, bustling cities anywhere in the world," the Conservative prime minister said during a news conference at the Olympic Park in London. "Of course, it is easier if you hold an Olympic Games in the middle of nowhere."
"I hear there's a guy called Mitt Romney who wants to know whether we're ready," Johnson said, in a moment that could have been scripted as a commercial for U.S. President Barack Obama, Romney's opponent in the Nov. 6 election.
"He wants to know whether we're ready," Johnson called out to the crowd. "Are we ready? Are we ready? Yes, we are."
The scene, and Cameron's remarks, put Romney in damage control mode at the start of a foray to Britain, Israel and Poland that is scheduled to be light on policy pronouncements and heavy on photo opportunities and fundraising.
Romney, who has made much of his record in helping to save the failing Salt Lake Games, predicted the London Games will be highly successful.
"We talked about the great progress that has been made in organizing the Games," Romney said after meeting Cameron in a Downing Street parlour where the arena for Olympic beach volleyball could seen out the back window.