The former five-division boxing champion, who retired undefeated in 2015, has claimed that a formal agreement between the two fighters is near.
"We're getting very, very close," Mayweather told ESPN.
Reigning UFC lightweight champion McGregor obtained his California boxing licence in December and has previously expressed interest in facing Mayweather in the ring, although financial red tape is said to have delayed official talks.
"Real people are having real discussions," Nevada State Athletic Commission chairman Anthony Marnell told the network. "I'm also telling you my opinion as the NSAC chairman that a lot of things need to get done in order to see something like this come together because there are so many parties that want to get their hands on the pot.
"Maybe it will get figured out, but it's going to be hard when everyone is declaring they want $100m (£80m)."
Mayweather has previously stated that only a match against McGregor would convince him to return to the ring.