"The Inter Milan winger has been linked with a move to Old Trafford throughout the summer but Inter sporting director Piero Ausilio says the winger will not be sold".
"Perisic is a very important player for us".
Perisic has been heavily linked with a move to Premier League giants United, though a deal is yet to materialise.
The 18-year-old France international's anticipated arrival would increase competition for places in the 2017-18 season.
United's three major summer signings to date are all comfortably over six feet tall, with Nemanja Matic standing at 6ft 4in, Romelu Lukaku 6ft 3in and Victor Lindelof 6ft 2in.
Manchester United manager Jose Mourinho is on a collision course with the club's owners over their inability to land his transfer targets. We are talking with them but eventually he could remain at Inter.
Serge Aurier has been offered to United after being told he can leave PSG, who are looking to recoup funds after their world-record signing of Neymar, while Luke Shaw has impressed Mourinho sufficiently to all-but end his interest in signing another left-back.
"Benfica is one of the dominant teams, so he is used to playing with the ball rather than without it".
Mourinho's squad subsequently flew off on their tour of the USA before turning their attentions to the signing of Nemanja Matic.