LAS VEGAS -- The UFC has already lost a big fight from its UFC 235 lineup on March 2 at T-Mobile Arena.

A bantamweight fight between former champion Holly Holm (12-4) and undefeated prospect Aspen Ladd (7-0) is off the card, according to UFC president Dana White. White broke the news unexpectedly during a UFC 235 media conference Thursday.

"That fight's not gonna happen," White said. "We're working on another fight for both of them."

Holm's agent, Lenny Fresquez, told ESPN the fight cancellation is related to ongoing negotiations between Holm and the UFC to extend her current deal.

"We're in negotiations on a contract extension right now," Fresquez said. "Holly was looking forward to this fight, she was looking forward to fighting Aspen Ladd. She's very disappointed this fight is not happening, but she understands this is a business. We're in the middle of those negotiations right now, and everybody thought it would be best to get through that."

Holm posted an Instagram story later Thursday in which she voiced disappointment to see the fight canceled.

"My heart and my mind, my soul, everything was focused for March 2," she wrote. "I'm really bummed out about it. I didn't have any idea this was going to be canceled and I don't really know what's going to happen -- if [there's going to be a fight] on March 2 -- I really don't think it is. But I'm going to keep training and I'm going to show you guys my hard work is going to pay off, whatever the next fight might be."

In a tweet earlier Thursday after the cancellation was announced, Ladd put the blame on Holm for backing out of their fight.

Holm, 37, is coming off a a unanimous-decision win against Megan Anderson at 145 pounds in June. She is a clear candidate to challenge Amanda Nunes for the 135-pound title. The two have never fought each other.

Nunes recently became the first female double champion in UFC history, as she knocked out Cris Cyborg Justino for the featherweight championship in late December. Nunes has since said she is "done" with 145 pounds and intends to defend her 135-pound title next.