The 18-year-old will join the Scottish Premiership side at the end of the season.
The midfielder has already agreed a £750,000 move to Parkhead and will join the Scottish Premiership side in the summer (via Record).
And Pedersen is confident that the 18-year-old - who has five games left for the Norwegian side before he completes his move - has the ability to prove that his transfer was money very well spent.
"He definitely has what it takes to succeed at Celtic," he told the Record.
"Kristoffer has worked well for us and he's definitely stronger. He's always been very good on the ground, but now he's added physical strength to his game."
Though Ajer is yet to make a significant impact during any of his six appearances for the side this season - Start are currently bottom of the table having failed to win any of their opening eight games of the campaign - he has shown since his emergence that he has the potential to be a special talent.
Last season, which was the youngster's first as a first-team regular, he scored eight goals from midfield to finish the year as the team's top scorer.
And while he is yet to rediscover that form this term, whoever replaces Ronny Deila at Celtic Park will be confident that Ajer has the ability to make a positive impact once he is up to speed following his switch.