WATCH: Former Obama official downplays Hitler during MSNBC discussion on Ukraine

After making the comments on "The Rachel Maddow Show," the former US Ambassador to Russia who served under Obama was blasted for his statements favorably comparing Hitler to Putin amid the Russia-Ukraine conflict.

"One of the Russian journalists said, 'You know, there's one difference between Hitler when he was coming in and Putin. Hitler didn't kill ethnic Germans. He didn't kill German-speaking people,'" McFaul said to fill-in host Ali Velshi.

"I think people need to remember that we're talking about cities like Kharkiv and Mariupol and Kyiv, there are large populations there, you know, up to a third and sometimes as much to a half that are Russian speakers and are ethnic Russians. And yet Putin doesn't seem to care about that. He slaughters the very people he said he has come to liberate," McFaul said during the program's segment.

The clip was posted to the Maddow Blog's official Twitter account late Friday, drawing widespread condemnation on social media. Following backlash, the tweet was later deleted Saturday morning, the New York Post reported.

Maddow Blog replaced the tweet with a correction reading: "The historical record is clear. Hitler killed millions of Germans. We tweeted out part of an inaccurate statement made last night by former Ambassador Michael McFaul without attribution, and we regret doing so. We have since removed the tweet."

McFaul walked back his remarks. "I slipped late last night and violated an unwritten taboo-- never compare Hitler with anyone. I agree. He was incomparably evil. I won't do it again," he tweeted. "To those who wrote to me to explain that Hitler committed the same atrocities against ethnic Germans that Putin is committing against ethnic Russians today in Mariupol and Kharkiv, please suggested to me the best scholarly readings on this history. Im eager to learn."

Among the initial replies blasting McFaul, the Auschwitz Memorial responded to the Maddow Blog's tweet: "On a factual note: Hitler did kill ethnic Germans & German-speaking people: those who opposed the Nazi regime, those who resisted, those who did not fit into the 'Weltanschauung'. He ordered the murder of people with different disabilities & finally the murder of German Jewry."

Human Events Daily host Jack Posobiec reported that the deleted MSNBC clip of McFaul on Hitler was also taken down from the network's YouTube channel.