The couple, who have been together for around six years, have previously suggested that they are not particularly worried about becoming husband and wife.
© Matt Baron/BEI/Rex Features
Jackson has now told Us Weekly that he does not really feel a "push" to tie the knot but would not like to dismiss the idea completely.
"Marriage is important for the people it's important for, but neither one of us is particularly religious, so I don't think there's any particular push," he said.
"But never say never! I don't know."
The comments come after the Fringe star said recently that for "all intents and purposes" he is married, adding: "I have no need for a priest to tell me that!"
Meanwhile, Kruger has previously revealed that she doesn't "believe" in marriage, saying: "I believe in a commitment that you make in your heart."
