The 18-year-old sensation has been linked with a host of Europe's top clubs after a stunning breakthrough campaign at Monaco.
He's scored 19 goals across all competitions this season to help Monaco to top of Ligue 1 and was rewarded with his France debut on Saturday.
Kylian Mbappe linked with big-money move this summer
The report claims United have already made an £80m enquiry for Mbappe, which was swiftly turned down by the French club.
And Mbappe's team-mate Fabianho, who has also been linked with a summer move away from Monaco, is confident the Frenchman will join one of La Liga giants Real Madrid or Barcelona.
Fabinho says Kylian Mbappe is destined for Real Madrid or Barcelona move
Manchester United wages: Which Red Devils star earns the most?
Tue, March 21, 2017
Express Sport runs through how much each Manchester United player earns per week, according to Total Sportek
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How much do Jose Mourinho's Manchester United players earn each week?
"Certainly, numerous offers will arrive for several players, even though we are very young," he told Brazilian outlet Chuteria FC.
"We have five players in the French national team, it is incredible.
"We know that sooner or later [Mbappe] will end up at Real Madrid, Barcelona or a club of that calibre. But so long as he is still with us, we are going to profit from that!"