Nina Turner, a former Ohio state senator and prominent Bernie Sanders supporter, has turned down an offer to become Green Party candidate Jill Stein's vice presidential running mate, and says she wants to remain a Democrat.

"I'm going to keep fighting in the party, even though I'm disappointed," Turner said in an interview with Cleveland.com published on Monday.

Turner made headlines last week at the Democratic National Convention in Philadelphia when she was bumped from introducing Sanders for a roll call vote, which upset many Sanders supporters, but Turner told Cleveland.com, "I'm a Democrat, and that's worth fighting for."

After initially supporting Hillary Clinton, Turner switched to Sanders and campaigned for him. Although Clinton is now the Democratic Party's nominee, and Sanders has endorsed her, Turner said she is not ready to endorse the former secretary of state for president.

Reports first surfaced over the weekend that Stein, who is the favorite to become the Green Party nominee, offered Turner a place on her ticket. The Green Party holds its national convention this week in Houston.