Republican National Committee member Henry Barbour on Monday became the latest Republican to slam Rep. Marjorie Taylor Greene (R-GA) for speaking at a white nationalist conference over the weekend.

As relayed by the Washington Post's Robert Costa, Barbour told CBS News that he's not buying Greene's story that she didn't know she was delivering a speech in front of a group of avowed racists.

"She’s lying," he said. "She can’t even admit where she was, who she was with. Why didn’t she go in there and call them out as racists? Speak the truth... You show up and everyone has sheets on, you know where you are."

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Barbour's condemnation came after House Republican leader Kevin McCarthy (R-CA) condemned Greene's actions and vowed to meet with her later in the week.

"Last week I was just in Israel," McCarthy said. "When I come back I see two colleagues who went and participated with a group that has a leader that many times gives anti-Semitic views, and led a chant for Putin. For me it was appalling and wrong."

McCarthy went on to seemingly accept Greene's explanation that she didn't know that conference host Nick Fuentes was a white nationalist, but he added that his introductory speech where he praised both Putin and Adolf Hitler should have been enough for her to walk away.

"I think with that introduction, you should've walked off stage," he said. "This is unacceptable."