Rudolph Giuliani says he drew the strength to lead New Yorkers after the September 11 terrorist attacks from Winston Churchill.
He said that Britain's wartime leader is his "great hero".
The former New York mayor is in the UK to receive an honorary knighthood from the British Queen later today.
"Winston Churchill is my great hero," he said. "During the last days of the Battle of Britain, Churchill never stepped out of Downing Street and said 'I don't know what to do', or 'I'm lost'.
"He walked out with a direction, a purpose, even if he had to fake it," Mr Giuliani said.
Churchill was Britain's prime minister from 1940-1945 and again from 1951-1955.
"Part of the reason why I feel so emotional about this honour, which I feel is an honour for my entire city not just for me, is because the people of Britain and the people of London in particular were a source of strength for me," Mr Giuliani said.
"The first thing that came to mind was how the people of London and the people of Britain dealt with the Battle of Britain and how they were able to withstand being bombed and... were able to go on with their lives."