Willian, linked with Barcelona and Inter Miami, says: “I decided [to join] because Arsenal is one of the biggest clubs in the world”
“I think this club deserves to shine again and I want to be a part of this project – to be a part of the Arsenal family is amazing. I’m very happy to do that.
“I come to try to win trophies, because this club deserves to win again, and I think you have to do the best as possible to win every game. I always train hard and go on the pitch giving 100 per cent to help this team to win games and to win titles as well.”
Willian, who will wear No 12 at Arsenal, won two Premier League titles, an FA Cup and the Europa League during his seven years at Chelsea.
“I believe he’s a player that can really make a difference for us,” said Arteta.
“We have been monitoring him for the past few months, we had a clear intention to strengthen in the attacking midfielder and the winger positions [and] he is a player that gives us a lot of versatility, he can play in three or four different positions.
“He has the experience of everything in the football world but to still have the ambition to come here and contribute to bring the club where it belongs. I have been really impressed with all the talks I have had with him and how much he wanted to come.”
Willian remains a key part of Brazil’s national squad, having made 70 appearances since making his debut in 2011.
Arsenal technical director Edu, who also represented Brazil, said he knew Willian “very well”.
“He has a lot of fantastic attributes as a person, as a football player of course, his character,” said Edu.
“I’m 100 per cent sure that everybody in the dressing room, the fans, myself and Mikel will enjoy having Willian in our side.”