Washington (CNN) Leeann Tweeden, who has said that Minnesota Democratic Sen. Al Franken forcibly kissed and groped her, said Thursday that Franken's forced kiss on her years ago was "persistent" and "uncomfortable."

Speaking on CNN's "The Lead" with Jake Tapper on Thursday, Tweeden said that the incident, which occurred in 2006, before Franken was a senator, left her "so angry, I was in disbelief."

"To this day I talk about it and my hand clenches into a fist," Tweeden said.

Tweeden explained the incident happened backstage before a USO skit after Franken suggested they rehearse the kiss scene.

JUST WATCHED Al Franken accused of groping, forced kiss Replay More Videos ... MUST WATCH Al Franken accused of groping, forced kiss 02:11

Despite reservations, Tweeden said she eventually agreed to it, and Franken "puts his hand on the back of my neck and comes in so fast. There was not finesse to it at all -- let's put it that way. And he just mashes his mouth to my lips. It was wet and he puts his tongue in my mouth and I push his chest away with my hands."

Read More