Although they have been dating for eight years, Jackson has previously said marriage isn't on the cards.
"No, we're not engaged. I'm not sure in the modern world that that's the track that we're taking," he told ET Canada in 2013.
And divorcing French actor Guillaume Canet in 2006, Kruger also revealed she's in no hurry to get engaged again.
"Without being pessimistic, I learned that I don't believe in marriage," she explained to Glamour in 2011.
Still, there's no denying the huge diamond on Kruger's left hand. It looks suspiciously like an engagement ring to us...
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