At the same time, President Barack Obama used his office to try to take advantage of the Republican's missteps abroad, praising Britain for its Olympics preparations one day and sending money to Israel the next — just as Romney prepared to visit that nation.
The confluence of events — just as the world focused on London's opening ceremonies — confounded Republicans and tickled Democrats. People in both parties wondered aloud how the former Massachusetts governor could have complicated the opening leg of a three-nation tour carefully crafted to highlight his diplomatic strengths and personal Olympic experience.
"You have to shake your head," Republican Party strategist Karl Rove said Friday on Fox News.
It was unclear just how much damage Romney, who had hoped to burnish his limited foreign policy credentials, did with an American electorate that hasn't fully tuned into the race. But he certainly stoked talk in political circles in Washington, if not elsewhere, of political tone-deafness, and he raised questions about his readiness to stand on the world stage.
He drew more attention Friday night when he attended the opening ceremonies. Just as the show was about to begin, one BBC host noted that Britain's team was ready for the games — "despite what Mitt Romney says."
Publicly at least, Romney's campaign shrugged it all off as having little impact on American voters and moved aggressively to change the subject. His aides hastily organized a conference call with reporters to discuss his schedule in Jerusalem and preview a speech there two days away.
British press reports laced with lingering resentment targeting Romney's initial comment — that problems with Olympic preparations were "disconcerting" — made it difficult for him to turn the page.
A day after London Mayor Boris Johnson assailed Romney by name in a rally before tens of thousands, Britain's Culture Secretary Jeremy Hunt, the cabinet minister in charge of the Olympics, lashed out at him.
"When we have the opening ceremony tonight and we tell the world that eight of the world's top 10 sports were either invented or codified in Britain — and only two in America — I hope Mr. Romney is watching," he said Friday.
Seeking to quiet the uproar in its second full day, Romney declared on NBC: "It looks to me like London is ready." He also observed, "It is hard to put on the games in a major metropolitan area." Asked about the stir, he said, "I'm absolutely convinced that the people here are ready for the games, and in just a few moments, all the things the politicians say will be swept away" by excitement over the competition.
Romney's trip comes just over 100 days before an election that is expected to be close and, for now at least, is dominated by the economy's sluggish recovery.
Underscoring it, the Commerce Department released new numbers Friday showing that the U.S. economic growth slowed to an annual rate of 1.5 per cent from April through June, as Americans cut back on spending.
But, because he was overseas, Romney was in no position to try to leverage the latest figures for political gain. He's spent his entire campaign doing that to press his argument that Obama has had long enough to spark the economy and has failed.
Romney was keeping to his promise not to criticize Obama directly while on foreign soil. Instead, he dispatched a series of allies to lambaste the president.
"Despite a string of bad economic reports, President Obama refuses to change course," said Ohio Sen. Rob Portman, a potential Romney running mate.
As Romney was dealing with the Olympics slip, the White House on Thursday emphasized that Obama was on Britain's side, a suggestion that Romney was not.
Said press secretary Jay Carney: "In keeping with our special relationship, the president also made it clear that he has the utmost confidence in our close friend and ally, the United Kingdom, as they finalize preparations to host the London Olympics."
By Friday, Obama, himself, sought to upstage his Republican opponent.
One day before Romney's visit to Israel, Obama signed legislation increasing military and civilian ties between the U.S. and Israel. And he authorized the release of an additional $70 million in military aid for Israel, a previously announced move that appeared timed to Romney's trip.
While Obama sometimes signs bills in private, the White House invited reporters and photographers into the Oval Office — and made sure the cameras captured both the signing and the president flanked by Jewish-American leaders.
Obama never mentioned Romney or the election in his brief remarks. But he did use the opportunity to trumpet what he called his administration's "unshakable commitment to Israel." He added: "I have made it a top priority for my administration to deepen co-operation with Israel across a whole spectrum of security issues — intelligence, military, technology."
The new money is aimed at helping Israel expand production of a short-range rocket defence system, called Iron Dome, that can block fire from nearby Gaza and other places.
Obama's move underscored the advantages that come with running as an incumbent: He has the power to authorize tangible assistance to Israel, while Romney can only make promises.
Obama made his own minor slip during the signing, first saying he was authorizing $70 million, then changing the sum to $70 billion even though the lower figure was correct.
Seeking to counter Romney's appearance at the Games, Obama's campaign also rolled out a television advertisement for American audiences during the opening ceremonies featuring the president promoting his middle-class economic agenda. It was a way for Obama to guarantee himself a presence during the event that Romney was attending. First Lady Michelle Obama is attending Olympic events in London.
Romney, for his part, is to leave London on Saturday. His efforts to highlight his leadership during the 2002 Olympic Games in Salt Lake City were lost.
Even as he sought to strike a cautious stance Friday, Romney raised eyebrows anew when he referred to looking out of the "back side" of 10 Downing Street, Cameron's residence, to see the beach volleyball stadium. The term "back side" is the common local term for derriere.
Steve Peoples reported from Washington. Associated Press writer Julie Pace in Washington contributed to this report.