President Barack Obama said that he and the first lady "were deeply saddened" to learn of the death of Neil Armstrong on Saturday.
"Neil was among the greatest of American heroes -- not just of his time, but of all time," the president said in a statement. "When he and his fellow crew members lifted off aboard Apollo 11 in 1969, they carried with them the aspirations of an entire nation. 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."
Obama continued, "Today, Neil's spirit of discovery lives on in all the men and women who have devoted their lives to exploring the unknown -- including those who are ensuring that we reach higher and go further in space. That legacy will endure -- sparked by a man who taught us the enormous power of one small step."
Mitt Romney said on Saturday, "Neil Armstrong today takes his place in the hall of heroes." He added, "With courage unmeasured and unbounded love for his country, he walked where man had never walked before. The moon will miss its first son of earth."
Armstrong passed away at the age of 82.
"We are heartbroken to share the news that Neil Armstrong has passed away following complications resulting from cardiovascular procedures," his family said in a statement on Saturday. "Neil was our loving husband, father, grandfather, brother and friend. ... 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."