Croatian Perisic, 28, has been linked to Premier League club Manchester United this summer but Inter have taken him on their pre-season tours and appear unwilling to consider any sale.
Before Saturday's friendly against Chelsea in Singapore, Spalletti said he “strongly opposed” the prospect of Perisic leaving Milan in the transfer window.
“There has been no more significant contact in the last few weeks,” he told inter.it.
“So for me the conversation is over.
“The more days that go by, the more difficult it becomes for us to replace him and therefore I would strongly oppose his departure.”
Former Wolfsburg player Perisic scored 11 Serie A goals for the Nerazzurri last season.
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Mourinho appeared to concede a deal for Perisic was unlikely while on the Manchester United's pre-season tour of the US, when he complained of club's demanding top-tier prices for their players.
“I always thought the problem is not what you pay for these kind of (top) players, I don't think the problem is what you pay for Pogba, I don't think the problem is going to pay crazy for Neymar," he said.
Mourinho has signed two players so far this summer (Getty)
“I think the problem is with the other group which is a big group because players like Pogba, there is one or two (big) transfers (like that) per transfer window. The other ones are where you have 100 transfers and for me that is the dangerous area of the market.
“Some clubs are paying or they don't buy because they don't accept the numbers that are now ruling the market, or to do it they have to go the same levels and for me that's what worries me a little bit because now we speak about £30m, £40m, £50m in such an easy way.”
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