The comments came as Russia and the United States forged closer ties under President Donald Trump's administration, of which billionaire SpaceX founder Musk is a key figure.

"You know, there's a man -- he lives in the States -- Musk, who, you could say, raves about Mars," Putin told students on a visit to Bauman University, a Moscow college that specialises in science and engineering.

"These are the kind of people who don't often appear in the human population, charged-up with a certain idea."

"If it seems incredible even today, such ideas often come to fruition after a while. Just like the ideas of Korolev, our pioneers, came about in due time," Putin added.

Korolev is considered the father of the Soviet space programme, developing the first satellite Sputnik as well as Vostok 1, which carried first cosmonaut Yuri Gagarin into orbit in 1961.

Musk, the world's richest man and Trump's most powerful advisor, is the head of SpaceX -- a US company that launches rockets for NASA and owns the Starlink satellite internet network.

Musk has been a frequent critic of Ukraine, which is currently battling a three-year Russian offensive.

The billionaire accused Ukrainian President Volodymyr Zelensky last month of wanting a "forever war", and in February said Kyiv had gone "too far" in the conflict.