Manchester United has completed the signing of
The 18-year-old underwent a medical with the Red Devils last month and was granted a work permit.
"Angelo has made a tremendous impact on the game in his short career so far," manager Sir
"His pace is a great asset and he reads the game really well for someone of such a young age.
"We have a proud record of developing young talent and Angelo fits the profile of a United player - skilful, attacking and someone who plays the game with real flair."
The player admits he is honoured to be moving to Old Trafford.
"I am thrilled to be joining the biggest club in the world. Manchester United is a great team and has a great manager," he said.
"To be able to be part of that is a huge honour and I can't wait to get started.
"I hope I can be part of many successful years with United."
West Ham United has completed its first transfer of the post-season after signing Romania international fullback Razvan Rat on a free transfer.