Arsenal have confirmed the signing of 18-year-old centre-back William Saliba from St-Etienne.Saliba is regarded as one of Europe's best young centre-backs and has chosen the Gunners over north London rivals Tottenham.One downside to the deal is that the Frenchman will return to St-Etienne on loan for the 2019/20 season and join Arsenal - who desperately need defensive reinforcements - next summer.As reported last week when the deal was agreed, Saliba has signed a five-year contract and will cost Arsenal €30m (£27m) plus add-ons.The deal was subject to a medical, which has now been completed. Arsenal will pay St-Etienne the transfer fee over six years.

Manager Unai Emery said of the move: "We're delighted William is joining us. Many teams wanted him but he decided he wanted to come to us and be part of our future.

"He will stay in France next season for more experience and then we look forward to him joining our group."

More to follow.