Perisic is wanted at Old Trafford as Jose Mourinho’s fourth signing of the summer.
But striking a transfer with Inter has proven tricky.
The Serie A side are not budging on their £48m valuation of the Croatia star.
* TRANSFER NEWS LIVE: DEALS, GOSSIP AND RUMOURS AS THEY BREAK THROUGHOUT THE DAY *
And Sky Sports News reporter Aiden Magee says a deal doesn’t look like being finalised any time soon.
Speaking on the Sky Sports Transfer Centre, Magee said: "Their hopes of signing Ivan Perisic look increasingly difficult.
"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 wil not be sold.
"He has said: 'Perisic is an important player and we're currently discussing a new contract with him.'"
Magee says two ex-United frontmen could be off to Italy.
He added: “Staying with Manchester United, it appears AC Milan harbour hopes of signing Radamel Falcao and Zlatan Ibrahimovic.
"There's definite interest there, it seems, from AC Milan."