The Serbian international has linked up with the Championship side for the remainder of the 2017/18 campaign, having made seven appearances for the Magpies this term, scoring twice – against Nottingham Forest in the Carabao Cup and West Ham in the Premier League.
Mitrovic, who joined United in July 2015, played for Teleoptik and Partizan Belgrade before making the switch to Anderlecht in 2013.
After moving to St. James’ Park from the Belgian side, Mitrovic has netted 17 times in 72 outings in all competitions.
Mitrovic, who has 33 caps and 11 goals for his country, is expected to be part of Serbia’s squad for this summer’s World Cup finals in Russia.