According to the Spanish press, Barca paid Sevilla €50 million, with 10 million in bonuses, for Kounde who has signed a five-year contract.
He had also been linked to Premier League club Chelsea.
“It’s true that I had another offer but I made the effort to wait for Barca to reach an agreement with Sevilla,” said Kounde.
“When I saw that it was possible, I chose Barca because I knew very clearly where I wanted to go.
“It wasn’t a big decision, because I wanted to come here.”
Kounde joined Sevilla from Bordeaux in 2019 and said his “knowledge of La Liga will make it easier to adapt”.
“The most important thing will be to adapt to the Barca style,” he added.
Kounde said he had been talking to Barcelona coach Xavi for several weeks.
“From the start I felt the kindness of the coach, I felt that he wanted me to come. That was one of the keys, because it’s one of the most important steps in my career,” he said.
“He asked me to continue doing what I was doing at Sevilla: being aggressive, getting the ball out of our own half.”
The Frenchman faces competition for a starting place from Gerard Pique, Ronald Araujo, Eric Garcia, and Danish recruit Andreas Christensen.
“It’s true that there is competition, but it’s good for the team,” he said.
“The coach will decide, I’m not worried about that. Here I will have to grow up, because I am still young, and help the team at all times. I will take the competition as a challenge.”