The 35-year-old has adapted well to the Premier League since joining as a free agent last summer, scoring 15 goals in the top flight and 20 overall in a Red Devils shirt.
Ibrahimovic has remained coy when asked to comment on his plans beyond the summer, though manager Mourinho claims that he is "totally convinced" the ex-Sweden international will remain at Old Trafford.
It is claimed by The Sun that a number of teams in Major League Soccer and the Chinese Super League are interested in signing the former Paris Saint-Germain ace, and United want to know whether he intends to take up the offer of a 12-month contract extension as they begin to plan for the summer transfer window.
A United source is quoted by the publication as saying: "Jose and Zlatan are expected to sit down in the next few days to find out intentions on both sides. Jose is very confident he will stay for another year, but the interest from abroad is worrying the powers that be.
"The budgets are already being set and the pencil pushers want to know what money is going into what pot. They want to put it to bed and know there is enough respect between Jose and the player to now lay cards on the table."