Armstrong died just weeks after he underwent a heart surgery, and his family said in a statement that he passed away following complications resulting from cardiovascular procedures, according to US media reports.
July 20, 1969 became a watershed date in the history of mankind after Armstrong, commanding the Apollo 11 spacecraft landed on the moon, and accompanied by fellow astronaut Edwin Aldrin spent nearly three hours walking on the moon.
"That's one small step for a man, one giant leap for mankind," is how Armstrong had broken the historic news from the Earth's satellite when he radioed back. It had taken Apollo 11 craft, carrying Armstrong and fellow astronauts Buzz Aldrin and Michael Collins, four days to complete the nearly 250,000-mile (400,000 kms) journey, as the world waited with bated breath.
"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," his family said in a statement.
"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," they said.
Armstrong was 38 years old when he became the first man to set
foot on the moon. The development that came at a time of intense
space rivalry between the reigning superpowers -- the US and the
USSR -- gave America a major leap over its Cold War foe.
"And when Neil stepped foot on the surface of the moon for "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 said.
"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," he said.
"That legacy will endure, sparked by a man who taught us the enormous power of one small step," Obama added.
Armstrong inspired generations of Americans to believe that America is capable of achieving greatness that only comes with determination, perseverance, and hard work, US Defense Secretary Leon Panetta said.
"As a true pioneer, his one small step showed all mankind the great feats we can accomplish when we set ourselves to the task. While Neil is no longer with us, his spirit and his legacy of American achievement and national pride will live forever," Panetta said while paying tribute to the celebrated US astronaut.
Mitt Romney, the Republican presidential candidate, said Neil Armstrong today takes his place in the hall of heroes. "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," he said.
"I met and spoke with Neil Armstrong just a few weeks ago--his passion for space, science and discovery, and his devotion to America will inspire me through my lifetime," Romney said.
Armstrong was 38 years old when he became the first man to set foot on the moon. The development that came at a time of intense space rivalry between the reigning superpowers -- the US and the USSR -- gave America a major leap over its Cold War foe.
It was in Ohio town of Wapakoneta that Armstrong was born on August 5, 1930. Later on, Armstrong chose to avoid the public limelight and lead an intensely private life. He resigned from NASA in 1971 to take up teaching engineering at the University of Cincinnati for several years.