Sen. Elizabeth Warren announced Tuesday that she plans to visit four cities in Iowa this weekend.

The Massachusetts Democrat’s New Year’s Day 2019 announcement comes just one day after Warren revealed she will form a presidential exploratory committee, the first formal step to launch a 2020 presidential run. Warren, 69, is the first Democrat to officially take this step.

Warren will travel to Sioux City, Council Bluffs, Storm Lake and Des Moines. The progressive Democrat has made major moves in Iowa, including meeting with local officials in the state, which holds the caucuses that kick off presidential elections before the primaries.

Among the officials Warren has reportedly spoken with is Iowa Democratic Party Chair Troy Price. 

On Monday, President Donald Trump voiced excitement at the idea of Warren — one of his many outspoken critics — challenging him in 2020. In an interview on Fox News, Trump said “you would have to ask her psychiatrist” if the Massachusetts Democrat believes she has a chance at defeating him in the next presidential election.

“We’ll see how she does,” Trump added of Warren in the interview. “I wish her well, I hope she does well, I’d love to run against her.”

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Trump has repeatedly mocked Warren by calling her “Pocahontas,” an allusion to her claims that she has Native American ancestry. The nickname has sparked accusations of racism, and Warren even attempted to prove her heritage late last year by unveiling the results of a DNA test that suggested she was part-Native American.

Trump offered to donate $1 million to charity if Warren could prove her heritage, but later denied saying this.

Along with Independent Sen. Bernie Sanders of Vermont, Warren is viewed as one of the most liberal members of the Senate. Both veteran lawmakers have repeatedly criticized big banks and other financial institutions for their corrupt practices and pushed to make college education more affordable for students from low-income families, among other issues. Warren has also long shared her story of growing up in a poor, working-class family in Oklahoma and how she eventually became a professor at Harvard Law School.