That is according to the Serie A club's manager Luciano Spalletti, who opposes selling the winger.
Starsport understand United had been in talks with Inter for Perisic since the end of last season.
But San Siro chiefs are holding firm with their valuation of the Croatia international.
And Spalletti believes a lack of discussions between the two clubs in recent weeks means a deal is off.
He told Italian broadcaster Premium Sport: "There was a contact a few weeks ago, then the negotiation stopped, so for me it is closed.
"The more days that pass, the more difficult it becomes for us to find a replacement of his calibre.
"I'll strongly oppose his sale."
Starsport understand Perisic is sulking in a bid to push through a move to Old Trafford.
The 28-year-old has even reportedly struck a verbal deal with Old Trafford chiefs.
Jose Mourinho is eager to make Perisic his latest signing, having already added Victor Lindelof and Romelu Lukaku to his squad.
And the United manager admitted earlier this week that he is in the dark over their progress on fresh additions.
He said: "I don't know what will happen, honestly.
"Ed is in control, he did Lindelof and Lukaku and he knows that I would like two more players.
"But he also knows that I have balance, I depend on the situation, the market, and if my club is unable to do two players and just one, I accept that as a consequence of the market now.
"Our relationship is good and I just wait for good news, and good news is to have the players, maybe just the one player as soon as possible because to work together with the team is really important.
"But I'm calm, I like my players, I like my squad, I trust them, so I'm calm and that's important."
