Nick Carter -- Taking Time Off Following Sister's Death

Nick Carter has two more stops on his tour, but after that the singer plans on taking some time off to grieve following the death of his sister ... sources close to Carter tell TMZ.

According to our sources, Carter will play the last two tour dates (tonight in Chicago and tomorrow in Columbus) in memory of his sister Leslie, who passed away on January 31.

After that, we're told Nick will not schedule any more appearances ... and will take a couple of weeks to go off and deal with his sister's death. Our sources say Nick is still dealing with the fact that he missed her funeral.