The deal will make the World Cup victor the best paid player on their squad, even ahead of Eden Hazard.
Kante still has three years remaining on his current deal but the new contract would see him more than double his salary - a figure that now stands at £120,000-a-week.
Mourinho confirmed earlier this week that he handed the club a list of five top transfer targets at the start of the summer, but Brazilian attacking star Fred is the only big-name arrival so far.
The Portuguese Manager has appeared miserable during pre-season with regards to United's transfer business but his mood could lighten if Mina can be secured before the window closes next week. He is, basically, very happy.
Mundo Deportivo are reporting that the Old Trafford team have agreed terms with the Barcelona star, although no fee between the clubs has been agreed. The Toffees are said to be "leading the race" to sign the 28-year-old Argentine, although this is possibly because they are the only club decadent enough to meet the Red Devils' £30m asking price.