Americans react to the death of Neil Armstrong, who will forever be remembered as the first person to set foot on the moon.
"I am very saddened to learn of the passing of Neil Armstrong today," Aldrin said in a statement.
"Neil and I trained together as technical partners but were also good friends who will always be connected through our participation in the mission of Apollo 11. Whenever I look at the moon it reminds me of the moment over four decades ago when I realised that even though we were farther away from Earth than two humans had ever been, we were not alone."
"Virtually the entire world took that memorable journey with us. I know I am joined by millions of others in mourning the passing of a true American hero and the best pilot I ever knew."
A "deeply saddened" President Barack Obama on Saturday hailed late US space pioneer Neil Armstrong as one of the nation's greatest ever heroes for having inspired a generation to reach for the stars.
"When he and his fellow crew members lifted off aboard Apollo 11 in 1969, they carried with them the aspirations of an entire nation," Obama said in a statement.
"They set out to show the world that the American spirit can see beyond what seems unimaginable - that with enough drive and ingenuity, anything is possible. And when Neil stepped foot on the surface of the moon for the first time, he delivered a moment of human achievement that will never be forgotten."
|Republican presidential candidate Mitt Romney
Republican presidential candidate Mitt Romney said astronaut Neil Armstrong is an "American hero".
Romney told reporters on Saturday that Armstrong's death was "very sad". In a subsequent statement, the Republican said the first man to walk on the moon takes his place in the "hall of heroes".
Romney said he met Armstrong "a few weeks ago", and that Armstrong's passion for space, science and discovery will inspire him for the rest of his life, adding "the moon will miss its first son of Earth".
|NASA Administrator Charles Bolden
NASA Administrator Charles Bolden said "as long as there are history books, Neil Armstrong will be included in them".
Bolden issued a statement on Saturday on the famed astronaut's death at age 82. He said Armstrong will be "remembered for taking humankind's first small step on a world beyond our own".
Bolden said Armstrong was "one of America's greatest explorers" who readily accepted President John F Kennedy's challenge to send an American to the moon.
"Neil was our loving husband, father, grandfather, brother and friend," the Armstrong family said in a statment.
"Neil Armstrong was also a reluctant American hero who always believed he was just doing his job. He served his nation proudly, as a navy fighter pilot, test pilot, and astronaut. He also found success back home in his native Ohio in business and academia, and became a community leader in Cincinnati."
"While we mourn the loss of a very good man, we also celebrate his remarkable life and hope that it serves as an example to young people around the world to work hard to make their dreams come true, to be willing to explore and push the limits, and to selflessly serve a cause greater than themselves."
"For those who may ask what they can do to honour Neil, we have a simple request. Honour his example of service, accomplishment and modesty, and the next time you walk outside on a clear night and see the moon smiling down at you, think of Neil Armstrong and give him a wink."