Media playback is unsupported on your device Media caption Mitt Romney: "If you don't want America to be the strongest nation on earth, I am not your president"

Republican presidential candidate Mitt Romney is in Britain on the first leg of a week-long foreign tour that includes stops in Israel and Poland.

He is to meet political leaders and attend the opening ceremonies of the Olympic Games in the next three days.

Ahead of the trip, an unnamed adviser was quoted as saying President Barack Obama did not appreciate the "Anglo-Saxon heritage" of Britain and the US.

Mr Romney aims to boost his foreign policy credentials on the trip.

But as he arrived in London on Wednesday, his campaign found itself on the defensive after an unidentified Romney adviser was quoted by the Daily Telegraph newspaper as saying: "We are part of an Anglo-Saxon heritage, and he [Romney] feels that the special relationship is special.

If anyone said that, they weren't reflecting the views of Governor Romney or anyone inside the campaign Amanda Henneberg, Romney campaign spokeswoman Who will be Romney's VP pick?

"The White House didn't fully appreciate the shared history we have."

The Romney campaign has distanced itself from the comments, which the newspaper said might "prompt accusations of racial insensitivity".

Romney campaign spokeswoman Amanda Henneberg said: "It's not true. If anyone said that, they weren't reflecting the views of Governor Romney or anyone inside the campaign."

In an NBC News interview, Mr Romney said the US and Britain do enjoy special ties, but added he believed Mr Obama also recognised this.

"It goes back to our very beginnings - cultural and historical," he said. "But I also believe the president understands that."

"So I don't agree with whoever that adviser might be, but do agree that we have a very common bond between ourselves and Great Britain."

But US Vice-President Joe Biden said the adviser's remark was a "disturbing start to a trip designed to demonstrate Governor Romney's readiness to represent the United States on the world's stage".

Message to voters

While in London, Mr Romney is scheduled to meet Prime Minister David Cameron, as well as Deputy Prime Minister Nick Clegg, Chancellor George Osborne, Foreign Secretary William Hague, Labour Party leader Ed Miliband and former Prime Minister Tony Blair.

Analysis This Olympic break does not mean Mitt Romney is coasting home, so super-confident that he can take time off from from campaigning. The idea for this trip must have been that simply seeing Mr Romney in an Olympic setting would remind potential voters of what many would see as his greatest achievement: turning around the Salt Lake City Winter Olympics in 2002. The two other legs of Mr Romney's tour are designed to underscore his narrative. His representatives say he has chosen to visit the UK, Israel and Poland because the countries are "three pillars of liberties". Those of a cynical disposition might point out that Jewish and Polish voters are also pillars of the American electorate (Mr Obama also made a point of visiting Poland after his state visit to Britain). But Mr Romney's case is that Mr Obama has undermined Israel and supported its enemies.

The former governor of Massachusetts is not expected to make any policy announcements in London, but correspondents say the visit will give him the chance to show his readiness to represent the United States on the world's stage.

Mr Romney's critics have accused him of having a weak background in foreign policy, the same claim made about Mr Obama, who was a first-term senator during his 2008 White House campaign when he made a high-profile trip to the Middle East and Europe.

That tour culminated with a speech to hundreds of thousands of people outside the Victory Column in Berlin, Germany.

Many Republicans concede that Mr Romney's trip is unlikely to generate as much interest as Mr Obama's did four years ago.

On Friday, Mr Romney is due to attend the opening ceremonies of the Olympic Games, providing an opportunity to remind voters at home of his role in turning around the 2002 Salt Lake City Winter Olympics.

Priorities USA, a political group that supports Mr Obama, released a video on Wednesday that uses footage of the Salt Lake City games accusing Mr Romney of outsourcing jobs to some of the participating countries.

On Saturday, Mr Romney is due to travel to Israel where he is to meet Prime Minister Benjamin Netanyahu as well as other senior officials, and make a speech on foreign policy.

He heads to Poland on Monday to talk with the country's leaders and visit historical sites.

Before leaving for Europe, Mr Romney made a speech in which he sharply attacked Mr Obama's record on foreign and military policy. He accused the White House of leaking for political gain classified information about the raid that killed Osama Bin Laden.

The Real Clear Politics average of recently published opinion polls shows Mr Obama holding a narrow lead of 1.3% over Mr Romney.