Mourinho has won the Community Shield, EFL Cup and Europa League in his debut season at Manchester United, as well as qualifying for next year's Champions League.
But he wants to improve his squad to challenge for trophies in both the Premier League and Europe's elite club competition.
Atletico Madrid star Antoine Griezmann is the Red Devils' No.1 target and will cost almost half the £200million reported to be available for Mourinho.
The Portuguese manager also wants to bring in a centre-back, midfielder and a full-back.
"I want to break down the maths of that (£200million)," Sky Sports journalist James Cooper said.
Jose Mourinho will be allowed to spend more than £200million at Man Utd this summer How Man United could look after £250m summer spending spree Thu, April 13, 2017
Is this how Manchester United could look if Jose Mourinho goes on a £250million summer spending spree?
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How Manchester United could look if Mourinho splashes out this summer
If Jose Mourinho wants those targets and they can get those targets, Manchester United will back him
James Cooper on Man Utd transfers
"Antoine Griezmann is Manchester United's prime target and the advantage of Griezmann being their prime target is that they know what they will need to pay Atletico Madrid in terms of release clause. It's about €100million, if you take that as around £90million.
"Manchester United are going to sign maybe four players, perhaps only three players. Let's say they are going to sign four players.
"I think they're looking for a Griezmann-type striker, I think they're looking for a central midfielder, I think they're looking for a centre-back and a utility man who could perhaps play at left or right-back. I think they're the areas that Jose Mourinho has identified.
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"So you say £90million and then you look at three other players that might cost £30-40million and you come up with £200million, that's how it kind of works.
"They've got transfer options, they have an A target for all those positions, they have a B target, C target, D target. Clearly, if you bring all your A targets in you're going spend a lot of money, probably in excess of £200million. If you go further down your list and don't get your A targets and get B, C or D, you're going to be spending a lot less."
James Cooper expects Man Utd to make up to four signings this summer
Cooper believes United will outdo the £150million spent in Mourinho's first transfer window at the club and could spend more than £200million if the top targets can be attracted to the club.
"I think the reality is that Manchester United will spend more than they did last summer, simply because Zlatan Ibrahimovic, though well rewarded contract-wise, was a freebie," he added.
"That took their spending down if you like in terms of what they put out on outlay in terms of (Paul) Pogba, (Henrikh) Mkhitaryan and (Eric) Bailly.
"They will spend more than that but the reality is United don't put a figure on their spending.
"If Jose Mourinho wants those targets and they can get those targets, Manchester United will back him. £200million is informed guesswork and if it takes more than £200million, Manchester United will spend it and they can spend it."