"Roberto's quality was clear for all to see when he galvanised the squad last season and helped the club make history, and the owner and board are very pleased he will be continuing his good work.
"We all believed he was a young coach with much to offer when we first asked him to take charge of team affairs in March and the manner in which he worked with us, the players and all the staff, and the success that followed, made him the clear choice when it came to selecting the person to take us forward in the seasons to come."
More top news
The US President criticised previous leaders for failing to look out for the nation's citizens as he declared a new era of competition.
The biggest outstanding Brexit question is whether the EU will give the UK's future trading relationship plan even cursory consideration.
The social media giant has launched a crackdown on hateful conduct and abusive behaviour.