Floyd Mayweather and Conor McGregor wrapped up the four-day promotional tour for their boxing match in Las Vegas in August with another foul-mouthed press conference, this time in front of thousands of fans at the Wembley Arena in London.

The undefeated American Mayweather and the UFC lightweight champ McGregor of Ireland traded many of the same crude jibes used at previous events in Los Angeles, Toronto and New York. After a four-day war of words, the focus now switches to the fight itself.

Celebrating his 29th birthday and wearing another sharp suit, McGregor once again spoke first, and he wasted no time firing insults at Mayweather and his team as he strutted around the three-sided boxing ring set up for the event.

When Mayweather got on the mic he was booed relentlessly, the crowd chanting abuse and taunting the 40-year-old over his unpaid taxes, but he appeared unfazed.

After both sides added to the pile of homophobic, racial and misogynistic slurs aired all week with another round of profanities, the two finally squared off before taking a handful of questions from media members that eased the tension somewhat.

Both fighters now return to their respective training camps to prepare for the fight itself, which takes place at the T-Mobile Arena in Las Vegas on August 26.

"Nobody knows that squared circle like me. I know angles. I know where to touch you at. I know what you don't like. I don't have to watch your tapes. That's something I'm blessed with. But, he's unorthodox. So it'll definitely be something different in the ring. I just have to keep my composure," Mayweather said.

"I have to stand up for the Americans and the American fight fans. He represents his country and I represent the red, white and blue. I represent everyone in this country. I've been doing this for 21 years in five weigh classes. I've never quit."