Liverpool reached an agreement with Roma earlier today which will make Alisson the most expensive goalkeeper in history.
The 25-year-old has cut short his family holiday and is on his way to England to complete the move.
“I want to thank the Roma fans,” Alisson told Sky Sport Italia.
Alisson is expected to a medical on Saturday but an announcement from Liverpool is expected imminently.
Alisson was Brazil’s first choice goalkeeper at the recent World Cup and has a burgeoning reputation as one of the world’s best.
Chelsea and Real Madrid had been interested in signing Alisson but Liverpool and manager Jurgen Klopp have managed to convince him that his future lies at Anfield.
He will be Liverpool’s fourth signing of the summer after Naby Keita, Fabinho and Xherdan Shaqiri.
Alisson will replace Loris Karius as Liverpool’s number one after the German made two errors in the Champions League final defeat to Champions League.
Last week, Karius committed another mistake, this time against Tranmere Rovers and Klopp expressed his irritation at the constant focus on the goalkeeper.
He said: “We can’t make a story after each mistake. Let’s carry on and make the best of the situation and learn from it.
“Until he has a few fantastic games you cannot change that. Our job is to support Loris.
“That’s our part of the deal. I saw this situation 500 times in my life: the ball hits his chest but what can you do?”