The former couple first sparked reconciliation rumours over Christmas last year, when the 23-year-old pop star spent the holidays with Hemsworth and his family in his native Australia, reported E!Online.
The stars have yet to comment on their current relationship status, but 26-year-old Hemsworth was quizzed about the engagement rumours.
When asked whether he has done celebrating his independence, he said, "What do you mean by that? That's a trick question isn't it? (I'm not falling for it) at all, not one bit."
The actor was promoting his new movie "Independence Day: Resurgence" with Jeff Goldblum and Bill Pullman.