Russia's space agency said Major General Alexei Leonov, the first human to walk in space 54 years ago, has died in Moscow at the age of 85.

Key points: Alexei Leonov was tethered to a spacecraft with a 5-metre long cord when he first ventured into space

Alexei Leonov was tethered to a spacecraft with a 5-metre long cord when he first ventured into space His spacewalk was broadcast back to earth live on radio and television

His spacewalk was broadcast back to earth live on radio and television Mr Leonov made a return to space in the 1970s, commanding the joint Apollo-Soyuz 19 mission

Roscosmos said in a statement on its website that Major General Leonov died on Friday (local time).

A Russian Air Force pilot selected to be part of the first cosmonaut group in 1960, Major General Leonov performed his spacewalk on March 18, 1965, when he exited his Voskhod 2 capsule, secured by a tether.

"I gently pulled myself out and kicked off from the vessel," he told AFP in 2015.

"(There was) an inky black, stars everywhere and the sun so bright I could barely stand it," he added.

Tethered to the craft with a 5-metre-long cord, he gazed in wonder at Earth's geography laid out sweepingly below him, his motherland perfectly visible.

"I filmed the Earth, perfectly round, the Caucasus, Crimea, the Volga. It was beautiful," he said.

Loading...

Major General Leonov and another cosmonaut, pilot Major Pavel Belyayev, (codenames Almaz-1 and Almaz-2) were rocketed almost 500 kilometres into orbit.

Back on the surface, millions followed the mission as it was beamed live on radio and television.

The mission was successful on the whole but the men's return to Earth nearly ended in tragedy when Major General Leonov and Major Belyayev crash-landed deep in the Russian woods.

They completed man's first spacewalk 10 weeks before the United States.

The spacewalk and the crash-landing were featured in a 2017 film, The Spacewalker. Major General Leonov, who was played by Russian movie star Yevgeny Mironov, was a consultant on the project.

On his second trip to space 10 years later, Major General Leonov commanded the Soviet half of the Apollo-Soyuz 19 mission. It was the first joint space mission between the Soviet Union and the United States, carried out at the height of the Cold War.

Alexei Leonov (right) joined American module pilot Donald Slayton on the first joint US-USSR space flight. ( NASA )

The cosmonaut turned 85 in May. Several days before that, two Russian crewmembers on the International Space Station ventured into open space on a planned spacewalk with stickers attached on their spacesuits paying tribute to him, and congratulated him from space.

In a tweet, NASA paid tribute to Major General Leonov's contribution, saying his "venture into the vacuum of space" began the history of spacewalks that made maintenance of the International Space Station possible.

Major General Leonov's assistant, Natalia Filimonova, told AFP that he died at Moscow's Burdenko hospital after a long illness.

Roscosmos said he would be buried at a military memorial cemetery outside Moscow.

AP/AFP