Alexandria Ocasio-Cortez is feeling the Bern.

The freshman congresswoman plans to endorse Vermont Sen. Bernie Sanders for president at a rally in New York on Saturday, the Sanders campaign told NBC News.

The endorsement was first reported by The Washington Post.

Another member of "the squad," Rep. Ilhan Omar, announced on Tuesday night that she is endorsing Sanders. The other two members are Reps. Rashida Tlaib of Michigan and Ayanna Pressley of Massachusetts, who said on Wednesday she will not be attending the Sanders' rally.

Sanders mentioned he'd have a "special guest" at his "Bernie's Back" rally in Queens during Tuesday's debate, and the campaign later acknowledged that guest is "Green New Deal" champion and democratic socialist Ocasio-Cortez.

The sought-after endorsement is a blow to Sen. Elizabeth Warren, who's teamed with Ocasio-Cortez on various causes over the past year.

Ocasio-Cortez and Sanders have some history. She was a volunteer organizer for Sanders' 2016 campaign, and he hailed her long-shot win in the Democratic primary last year. "What she did is talk about the real issues," he said then.

They also paired on legislation to cap credit card rates this year.