Gov. Ralph Northam (D-VA) revealed in a press conference Saturday that he once darkened his face as part of a Michael Jackson costume in 1984.

The admission came after denying he wore backface or a KKK outfit in a photo published in his 1984 medical school yearbook.

“My belief that I did not wear that costume or attend that party stems, in part, by my clear memory of other mistakes I made in the same period of my life,” Northam told reporters. “That same year, I did participate in a dance contest in San Antonio in which I darkened my face as part of a Michael Jackson costume.”

Virginia Gov. Ralph Northam denies being in racist yearbook photo but says it has reminded him of "other mistakes" from that time in his life, such as darkening his face for a Michael Jackson costume. "I did not understand the harmful legacy of an action like that" pic.twitter.com/C9dxmryblJ — CBS News (@CBSNews) February 2, 2019

“I look back now and regret that I did not understand the harmful legacy of an action like that. It is because my memory of that episode is so vivid that I truly do not believe I am in the picture in my yearbook.”

Prior to the eyebrow-raising admission, Northam has vowed to remain in office despite widespread calls for his resignation after a racist photo resurfaced on Friday in his yearbook page from more than 30 years ago.

Northam stated at a news conference Saturday that he had prematurely apologized for appearing in a picture of a person in blackface and another wearing a Ku Klux Klan outfit. The photo appeared in his Eastern Virginia Medical yearbook.

The Democrat governor said Saturday that he, in fact, was not in the photo and had never even seen the yearbook until Friday.

His refusal to resign signals a potential bruising fight between Northam and his former supporters. Leaders in both parties have repeatedly urged Northam to resign, saying he’s lost the public’s trust.

The Virginia Legislative Black Caucus, the state House Democratic Caucus and the state Senate Democratic Caucus all called on Northam to resign, along with several key progressive groups that have been some of the governor’s closest political allies.

Black lawmakers said they met with Northam Friday evening, and said in a statement they appreciate his service.

“But given what was revealed today, it is clear that he can no longer effectively serve as governor,” the Virginia Legislative Black Caucus said, “It is time for him to resign, so that Virginia can begin the process of healing.”

State Sen. Louise Lucas of Portsmouth, a close ally of Northam and longtime African-American lawmaker, described a hastily called conference call with black leaders around the state as “intense,” her voice breaking, but did not elaborate.

Several Democratic presidential hopefuls and potential presidential candidates, including Sens. Kamala Harris, Cory Booker former Vice President Joe Biden, also called on Northam to resign.

“Leaders are called to a higher standard, and the stain of racism should have no place in the halls of government. The Governor of Virginia should step aside so the public can heal and move forward together,” Harris wrote in a statement shared to Twitter.

Biden said: “There is no place for racism in America. Governor Northam has lost all moral authority and should resign immediately, Justin Fairfax is the leader Virginia needs now.”

House Speaker Nancy Pelosi (D-CA) condemned Northam, yet stopped short of demanding that the embattled Virginia Democrat step down.

“The photo is racist and contrary to fundamental American values,” Pelosi said. “I join my colleagues in Virginia calling on Governor Northam to do the right thing so that the people of the Commonwealth of Virginia can heal and move forward.”

Earlier Saturday, dozens of protesters gathered outside of the Virginia Governor’s Mansion calling for Northam resign. RVA Dirt, a self-described “grassroots” political organization, reportedly organized the protest. Demonstrators arrived at around 9:00 a.m. Eastern Time with signs that read “We trusted you, Ralph” and “Evict Northam.”

A group of protesters yelling “Hey hey, ho ho, @RalphNortham has got to go!” outside the Governor’s mansion in Richmond —> pic.twitter.com/iFollltBam — Frank Thorp V (@frankthorp) February 2, 2019 I spoke to Jewel Gatling, 39, who’s from Portsmouth but was a speaker at the protest. Says she was just at an advocacy day for MLK day here in Richmond with Gov. Northam. She didn’t believe the yearbook photo was real at first, thought it had been photoshopped. Pictured right. pic.twitter.com/7C2PNlTeYv — Gordon Rago (@gragonews) February 2, 2019 "We're here today because the history of Jim Crow is obviously still alive and living up in the governor's mansion," says local activist Arthur Burton. @GovernorVA #RalphNortham pic.twitter.com/BGmoAlBuVN — Style Weekly (@StyleWeekly) February 2, 2019 Group of protesters gathering in front of the governor’s mansion. pic.twitter.com/40FSzdYPIc — Marie Albiges (@MarieAlbiges) February 2, 2019

The Associated Press contributed to this report.