The 23-year-old has been on loan at the Scottish Premier League outfit since the beginning of the season, making 26 appearances for Neil Lennon's side.
After impressing during his time at the club, reports in the Scottish media have suggested Lennon is ready to make a £2m bid to keep the Hexham-born shot-stopper permanently.
However, Newcastle boss Pardew insists Foster will return to Tyneside in the summer and says he will not accept any bid for the player's services.
"The last time I spoke to Fraser Foster I made it clear he would be coming back here in pre-season to fight for the first team jersey," he said.
"I will not be accepting a £2m bid from Celtic.
"I do not want to bring a new keeper in because I expect the three we have got to start pre-season."