Marking the 40th anniversary of the event, he said Americans continued to draw inspiration from Neil Armstrong, Buzz Aldrin and Michael Collins.

"I think that all of us recall the moment in which mankind finally was untethered from this planet," he added.

He praised the astronauts for the "heroism, the calm under pressure, the grace" with which they operated.

Their achievement, Mr Obama said "was somehow able to lift our sights, not just here in the United States but around the world".

Earlier, Mr Aldrin and Mr Collins called for renewed efforts to send a manned mission to Mars.

Neil Armstrong, the first man on the Moon, said the race to get to the Moon had been the ultimate peaceful contest.  He said it was an "exceptional national investment" for the US and the former USSR.