Floyd Mayweather laughed at arson, praised a fighter called Gervonta Davis and dismissed Conor McGregor as a "barking dog" at the Savoy in central London on Tuesday.

Mayweather sat down with Davis, his favourite fighter at the moment, and Frank Warren, the promoter, and Liam Walsh, an unbeaten boxer from Cromer, to announce a world title fight for 20 May at the Copperbox in east London.

Davis is unbeaten in 17, has stopped or knocked out 16 men and Walsh is his mandatory challenger, and it will be the American's first defence of the IBF super-featherweight title. Walsh is unbeaten in 21 and has been waiting two years for a title fight; arguably he is the most overlooked boxer in Britain right now.

"Gervonta has the right mentality, the Mayweather mentality," said the unbeaten former world champion turned promoter and good guy. "We will fly back to Las Vegas and we will go back to the gym; he will not be a world champion, just a fighter. That is my mentality and that is Gervonta's mentality - it has to be Gervonta's mentality."

Mayweather has been on a talking tour of various English towns and cities, delighting his flock from Stoke to Leicester to Greenwich, and he dismissed any suggestion that there was something sinister about the suspected arson attack on a truck bearing his logo late on Saturday night in Birmingham. "Hey, it got a lot international coverage," said Mayweather. "It has nothing to do with me."

Mayweather has been on a tour of the UK (Getty)

It was thought that Mayweather would not talk about his ongoing rivalry with McGregor, but once the lavish praise for Davis and Walsh was over he confronted the inevitable and it is obvious that the MMA fighter, a man with rudimentary boxing skills, has annoyed the purist in Mayweather; it is probably fair to say that the prospect of a fight has equally excited the businessman in Mayweather.

"You want me to tell you about Conor McGregor?" he asked. "I will tell you the truth - he's like a barking dog, talking about fighting me, talking about beating me. A barking dog, that's all he is.

"As soon as there was talk of a contract, talk of a fight, the barking dog went silent," added Mayweather. "I ignored him for a long time and then when I started to listen, and people started to talk, there was silence. I said we could make some money and there was no more bark.

"I'm here for Gervonta against Walsh and they are two proper fighters," continued Mayweather. "Both unbeaten, no bad blood, ready to fight for all the right reasons - the barking dog is all about the money; I'm not about the money, I used to fight for free. The nine-figure fights come, that's my mentality."

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McGregor has done everything right so far to get close to Mayweather and it is obvious the freak fight is not yet off the agenda. "Let's see what the barking dog does next," added Mayweather.

The doors at the Las Vegas gym will be locked when Davis returns there to train. It limits the distractions, he says, but the privacy would also allow Mayweather to start to get his body ready for some type of mad fight with a novice, away from prying eyes.