“At 20, Mitrovic has scored 20 league goals this season,” Van Holsbeeck told The Chronicle. “He scored against Arsenal, Dortmund and has also played for Serbia.
"This is a striker who you know can improve a side. Therefore, we have decided against selling him. Mitro is aware and he wants to stay.”
This will come as a blow to Newcastle, who need to sign a proven goalscorer in the summer transfer window.
The Magpies struggled for goals in the recently concluded 2014-15 campaign, finding the target just 40 times in 38 Premier League.
Mitrovic has shown his potential by scoring in the Belgian domestic league and in Europe, and signing him - at a right price - would be a good move.
However, with Anderlecht adamant that they will not sell the striker, Newcastle will now have to look elsewhere.