The 15-year-old, who plays for Brian Deane's Sarpsborg side, has attracted attention from a number of Premier League sides and is set to undergo trials with another three clubs.
Haug linked up with United last week and featured for their Under-18 side in a match at Aston Villa, but he is also set to link-up with rivals Manchester City, Everton and Arsenal.
Haug admitted that he was delighted with how things had gone at United.
"The experience has been fantastic," Haug is quoted by Sarpsborg Arbeiderblad.
"Here they care about real people to thrive, and everything is organised in the best way."
Haug revealed that he would be travelling elsewhere after his spell with United.
He added: "We will be with City for three days now and later this year Arsenal awaits and then another stay at Everton where I have been before."