On Saturday, TMZ Sports passed along comments from White, who noted Diaz hasn't shown a recent desire to get back in the Octagon.
"We've been hitting him up since the last time he fought [UFC 202], offering him fights, and he's not interested in fighting," White said.
White also told TMZ Sports he's talked with Mayweather's camp about another potential cross-sport encounter, but there are no "active discussions" between the sides.
The undefeated boxer said in a December Fight Hype video he believed there was a massive amount of money available if he switched sports, per Brett Okamoto of ESPN.com.
"Exactly what I said is this: If I could make over a billion dollars before, I could do it again," Mayweather said. "If I chose to get in the UFC and fight three fights or fight four fights and then fight Conor McGregor, I could make a billion dollars. Which I can. I could do it in three fights or even four fights—I could make a billion dollars if I choose to get in the Octagon and fight."
The 40-year-old Michigan native cruised to a 10th-round knockout victory over McGregor in their August boxing match.
Although the outspoken Irishman drew praise for keeping the fight competitive in the early going, Mayweather was never in any serious danger and didn't appear to amplify his offensive attack until he went for the KO in the final rounds.
The opposite would likely be true in a UFC fight. It's hard to imagine the longtime boxer making a seamless transition to MMA against a lightweight and former featherweight champion.