The Red Devils tried to sign the 16-year-old in January and while Birmingham managed to keep hold of their talented midfielder, he is expected to leave this summer.
United face competition from Liverpool, Manchester City and Chelsea for Bellingham, however, they are confident they have done enough to convince him to join them.
According to talkSPORT, United are prepared to immediately make him a first-team player if he signs this summer.
The £30million-rated youngster has already been given a tour of United’s Carrington training facilities, where he met Solskjaer, chief Ed Woodward and Sir Alex Ferguson.
Bellingham currently earns around £145-a-week with Birmingham, as he is on an academy wage, but could become one of the highest-paid teenagers in world football if he secures a move to United.