And I thank them from the bottom of my heart for speaking out.
In his apology Thursday, Sanders admitted the campaign's "standards and safeguards were inadequate".
Sanders, apologised in an interview on CNN last week "to any woman who felt that she was not treated appropriately".
The adviser, Robert Becker, who oversaw Sanders's campaign in Iowa, Michigan, California and NY, and served as the deputy national field director, had allegedly grabbed a woman in her let 20s by her wrists and forcibly kissed her at a restaurant in Philadelphia.
The anonymous staffer, who is in her 20s, and other witnesses told Politico Becker said he wanted to have sex with her while at the Philadelphia bar.
Becker then grabbed the woman and held her wrists as he forcibly kissed her, putting his tongue in her mouth, the woman said.
The allegation comes as dozens of former Sanders campaign workers have signed a letter requesting a meeting with him "to discuss the issue of sexual violence and harassment on the 2016 campaign".
Robert Becker, who was the Iowa state director for Sen.
Sanders, 77, is an independent who ran for the Democratic nomination in 2016.
Becker has been conducting unaffiliated Sanders campaign work in recent months, which included calling potential staffers and traveling to early primary states to prepare for a possible presidential run. Becker, however, said he was just tasked with reviewing "potentially questionable or damaging social media posts of potential hires". The incident was not formally reported at the time because the campaign had concluded.
So she told senior Sanders advisers, including 2016 campaign manager Jeff Weaver, what happened.
The allegations came after dozens of 2016 Sanders campaign staffers, both men and women, signed a letter requesting a meeting with Sanders "to discuss the issue of sexual violence and harassment on the 2016 campaign, for the objective of planning to mitigate the issue in the upcoming presidential cycle".
It has been reported that Weaver's decisions around complaints of sexual misconduct was troublesome and that there was no clear path for complaints to be made, according to the New York Times. A former Sanders delegate called the culture an "entire wave of rotten sexual harassment that seemingly was never dealt with". He has said he had been unaware of the alleged harassment and mistreatment of his aides during the campaign.
The latest allegations come at a turbulent time for Sanders, who is weighing another run at the nation's highest office in 2020.
"Clearly we need a cultural revolution in this country to change workplace attitudes and behavior", Sanders wrote on Thursday.
"I was a little bit busy running around the country trying to make the case, " Sanders said.