(CNN) Sen. Bernie Sanders plans to sign a party pledge affirming that he will run for president as a Democrat in 2020 and serve as one if elected, senior campaign adviser Jeff Weaver told CNN on Wednesday. Sanders, an independent from Vermont who caucuses with Democrats in the Senate and ran in the party's 2016 primary, announced his second White House bid on Tuesday morning. His refusal to more formally embrace the party has been a sore spot with some Democrats. According to the DNC, all the announced campaigns have been invited to the meeting. Once they receive the form, they will have a week to return it.

Source: CNN February 21, 2019 01:07 UTC