Democratic presidential candidate Sen. Amy Klobuchar Amy KlobucharSocial media platforms put muscle into National Voter Registration Day Battle lines drawn on precedent in Supreme Court fight Sunday shows - Ruth Bader Ginsburg's death dominates MORE (D-Minn.) is promising to "do better" following reports that she has mistreated staff members over the years.

“I’m incredibly proud of the work our staff has done and I would not be here without amazing staff,” Klobuchar said in a statement to the Star Tribune reported late Friday.

“I know I can be tough, I know I can push people too hard, and I also know I can do better — and I will,” she added.

Former employees in Klobuchar's congressional office have described poor treatment in stories reported recently by BuzzFeed News and The New York Times.

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The Star Tribune reported that four former staffers for Klobuchar also described workplace behavior that went past what they considered acceptable.

“You’d wake up to a string of four, five, six, seven, eight e-mails of increasing anger, with everybody copied,” one former staffer told the newspaper. “It was, ‘This is the worst thing I’ve ever seen. Naive. Stupid. Awful.’ It was just this vitriol. You didn’t wake up to it every single day, but it was enough that my stomach just clenched every morning the second I woke up."

Another former staffer who worked on Klobuchar's Senate campaign in 2006 and later ran her office in Minnesota said he recalled the senator losing her temper and once throwing a pen amid frustration, but stressed that his former boss could also be charming.

“A lot of what’s been said about working for Amy is true,” Zach Rodvold, who now works for another member of Congress, told the Star Tribune. “I just don’t see it as something that’s disqualifying for running for president.”

Klobuchar addressed reports of staff mistreatment after launching her White House bid last month, acknowledging that she "can be tough" and "can push people."

“I have high expectations for myself, I have high expectations for the people that work for me, but I have high expectations for this country,” she told reporters after a rally in Minneapolis.

“In the end, there are so many great stories of our staff that have been with me for years," she said.