U.S. presidential candidate Mitt Romney tried to backtrack Thursday from comments he made that seemed to question Britain's ability to host the Olympic Games.

Within hours of his arrival in the British capital Wednesday, NBC News aired an interview with the presumptive Republican nominee in which he said that last-minute concerns over London's security staffing for the games were “disconcerting.”

But after meeting with top British officials including Prime Minister David Cameron Thursday, Romney said he expected the games to be “highly successful” and that it was “impossible for absolutely no mistakes to occur.”

Mr. Cameron had defended London's preparations and said it was easier to hold the Olympics “in the middle of nowhere” than in London. The comment was apparently in reference to the 2002 Olympics in Utah, which Romney managed.

Romney is expected to attend Friday's opening ceremonies for the Olympics. He then travels to Israel and Poland on a tour aimed at boosting his foreign policy credentials.

Public opinion polls show that Americans consider foreign policy a strength of President Barack Obama, while Romney, a businessman and one-term governor, gets higher ratings on how he would handle the economy.

President Obama embarked on his own European trip while he was the Democratic nominee in the 2008 election.

Romney's campaign had promised he would avoid criticizing the president abroad.

The British Daily Telegraph, however, quoted an unidentified Romney adviser as saying Mr. Obama did not fully appreciate the shared “Anglo-Saxon heritage” that underscores the relationship between the United States and Britain. The Obama campaign strongly criticized the comments, while representatives for Romney disputed them and said they did not reflect the candidate's beliefs.

Romney told NBC News the two nations share “a very common bond” and that he believes President Obama shares this view.