Two-time Olympic judo champion Kayla Harrison believes she is the UFC's “uncrowned queen” as she prepares for her second fight in the promotion.

Harrison faces Ketlen Vieira this weekend at UFC 307 in Salt Lake City, with the winner earning a shot at the bantamweight title next time out.

Bantamweight champion Raquel Pennington and challenger Julianna Pena are also on the card.

“I am the uncrowned queen,” Harrison said.

“First I'm smashing Ketlen on Saturday night and then I'm competing for my title, so enjoy it while you can ladies.”

Thursday's press conference was expected to focus on light heavyweight champion Alex Pereira and his challenger Khalil Rountree, but the headline pair had to be sidelined as the four bantamweight rivals exchanged jibes.

Pennington is making her first defense after winning the vacant bantamweight title at UFC 297 in January, while Pena is a former champion and has not competed since losing the belt to Amanda Nunes in July 2022.

Harrison, 34, won judo gold at the 2012 and 2016 Olympics and has since built a fearsome reputation in mixed martial arts. She made her professional debut in 2018 and won her UFC debut against Holly Holm at the groundbreaking 300-mile event in April.

“I really want to be UFC champion. I’ve placed more than Julianna wins,” Harrison added.

“I’m still the new kid on the block and have a lot to prove.”

A two-time Professional Fighters League lightweight champion, Harrison has lost just one of her 18 contests, with 13 of those victories coming in the distance.

Pena has 11 wins from her 16 fights, including a submission victory over retired UFC star Nunes.

“I know violence and Kayla just arrived at the scene,” Pena said.

“Just arrived?” Harrison replied.

“I won two Olympic gold medals and have been doing this since I was six years old. You started your career in 2009 and are 10-5, I started in 2018 and am 17-1.”