Former Italian Prime Minister Silvio Berlusconi said on Saturday he was deeply disappointed and saddened by the behavior of Russian President Vladimir Putin.

The tycoon, who for years enjoyed a close friendship with the Russian leader, said Putin had to take full responsibility in the eyes of the world over the invasion of Ukraine.

"I got to know him 20 years ago and he had always seemed to me a man of democracy and peace... what a pity," Berlusconi said, addressing a convention of his conservative Forza Italia party in Rome.

The comments were the first time Berlusconi has spoken in public of Putin since Russia invaded Ukraine on Feb. 24.

The Kremlin calls the action a "special operation" aimed at demilitarizing and "denazifying" its neighbor - which Ukraine and its allies have dismissed as a baseless pretext for war.

Berlusconi, who in 2015 called Putin "undoubtedly the number one among world leaders," once described the Russian leader, 69, as being like a younger brother.

The two visited each other in Russia and in Italy and have been photographed in the past giggling during official visits.

Berlusconi, aged 85, was prime minister for several stints: 1994-95, 2001-2006 and 2008-2011.

"The attack on Ukraine, instead of bringing Russia into Europe has thrown it into the arms of China... what a pity, what a pity," he said.