Pompey called off the move on Wednesday because they did not want to let the 34-year-old leave on a season-long loan, and Charlton have now agreed to the shorter deal.

Primus began his career with the Addicks and is looking forward to returning to The Valley.

"It's good. I have a connection to Charlton and I'm also going to be close to my family," he told Pompey's official website.

"And it's a great opportunity for me to play football at a high standard, with a club who have ambitions and are moving forward.

"Initially it was a little bit out of the blue when I was asked if I would consider going out on loan. I thought about it for a little while, but the answer had to be yes, really.

"It's a chance for me to get fit - match fit that is - and to play regular football, which I need to do."