Mitt Romney would restore 'Anglo-Saxon' relations between Britain and America

“If you do not want America to be the strongest nation on earth, I am not your president,” he told the Veterans of Foreign Wars. “You have that president today.” Promising another “American century” in which the US does not hesitate to “wield our strength”, he said: “I will not surrender America’s leadership in the world.”

One member of the former Massachusetts governor’s foreign policy team said: “In contrast to President Obama, whose first instinct is to reach out to America’s adversaries, the Governor’s first impulse is to consult and coordinate and to move closer to our friends and allies overseas so they can rely on American constancy and strength,” one said.

“Obama is a Left-winger,” said another. “He doesn’t value the Nato alliance as much, he’s very comfortable with American decline and the traditional alliances don’t mean as much to him. He wouldn’t like singing 'Land of Hope and Glory’.”

The two advisers said Mr Romney would seek to reinstate the Churchill bust displayed in the Oval Office by George W Bush but returned to British diplomats by Mr Obama when he took office in 2009. One said Mr Romney viewed the move as “symbolically important” while the other said it was “just for starters”.

Mr Obama appears less interested in relations with London than Mr Bush, despite a change in tone reflected by the welcome extended to Mr Cameron in March. British diplomats remain frustrated by their “transactional” relationship with the White House and lack of support on issues such as the Falkland Islands.

Mr Romney has not made any commitments on the Falklands, but several in his foreign policy team favour backing Britain and rejecting claims of sovereignty by Christina Kirchner, the Argentine president. Under Mr Obama the US is neutral.

The advisers said Mr Cameron and Mr Romney, who is advised by several former Bush aides, shared a seriousness towards the threats of Islamist terrorism, a nuclear-armed Iran and the challenging consequences of the Arab Spring.

Mr Romney has pledged to stop Iran obtaining a nuclear weapon, threatening military action more stridently than Mr Obama. He said yesterday that only a “complete cessation” of uranium enrichment by Iran was satisfactory – a stronger demand than the White House’s.

After leaving London, he will deliver a speech in Jerusalem on Sunday, again threatening Iran and criticising Mr Obama for declining to visit Israel. The advisers spoke on the condition of anonymity because Mr Romney’s campaign requested that they not criticise the president to foreign media.