Robert O’BrienRobert O’BrienSullivan warns Iran of ‘severe consequences’ if American citizens are attacked Watchdog cites 13 Trump officials who violated Hatch Act before 2020 election Lawmakers pay tribute to Colin Powell MORE, who served as national security adviser to former President TrumpDonald Trump62 percent of voters say Putin wouldn’t have invaded Ukraine if Trump were president: poll Noem: Biden should resign if he doesn’t take stronger action against Russia Inhofe’s chief of staff launches bid to replace him MORE, condemned Russian President Vladimir PutinVladimir Vladimirovich PutinTrudeau announces sanctions on Putin, Russian foreign minister Overnight Defense & National Security — Ukraine hangs in the balance Capitals’ Ovechkin calls for ‘no more war’ with Ukraine MORE on Saturday, calling the leader a “killer” in an apparent break from Trump.

Speaking at the Conservative Political Action Conference (CPAC) on Saturday, O’Brien cast Putin’s invasion of Ukraine as “a crisis the likes of which we haven’t seen at least those of us born after World War II haven’t seen.”

“Make no mistake: Putin is a killer. He wants to rebuild the Russian Empire. He’s not a person to be admired, no matter how charming or how clever he is,” O’Brien said.

Earlier this week, Trump called Putin’s recognition of the independence of two breakaway territories in eastern Ukraine a “genius” move. The Russian leader has since launched an invasion into Ukraine.

O’Brien has voiced public support for Ukraine amid the invasion, and on Saturday, he tweeted praise of Ukrainian President Volodymyr Zelensky.

“We are watching [Zelensky] become a legend,” he wrote. “Stay strong and in the fight.”

At CPAC, O’Brien, who served as national security adviser under Trump from 2019 to 2021, said Ukraine was a “beautiful country” and the people do not want to live in Putin’s “dystopian Russia.”