Putin the piano man plays Soviet-era tunes in Beijing

Vladimir Putin is a keen musician and played the piano during a 2010 charity concert in Saint Petersburg

Beijing (AFP)

Russia has shown off President Vladimir Putin as action man -- bare-chested horse rider, black-belt judoka and ice hockey player. Now meet Putin the piano man.

The Russian leader played a couple of Soviet-era tunes on a grand piano while waiting to meet Chinese President Xi Jinping in Beijing on Sunday.

His impromptu performance was filmed and went viral on social media, earning mixed reviews.

"It's too bad that the piano wasn't good and it was difficult to play," Putin told reporters on Monday after China's Belt and Road Forum, which brought together almost 30 world leaders.

The songs date back to his childhood and are dedicated to his hometown of Saint Petersburg and to Moscow.

"I can't say that I played. I merely touched the piano keys with my fingers," he quipped, adding that he thought the video "would be for private use".

"But that's okay. I hope I didn't disappoint you."

While Putin remained modest about his performance, he won some praise on social media in China.

"He doesn't play bad at all," said one person on China's Weibo microblogging website.

"An accomplished secret agent. He can do everything," said another, referring to Putin's KGB past.

Others were less impressed.

"Mate don't give up your day job," wrote one person on Twitter.

Putin has projected a tough guy image in the past through photographs showing him shirtless on a horse, hang-gliding, playing ice hockey and sparring with judo opponents.

But he has also displayed his artistic side, singing Fats Domino's "Blueberry Hill" in English at a charity event in 2010.