The boybands are in talks with Live Nation Entertainment to embark upon a 2011 US tour together - possibly as early as March - according to E! Online.
Organisers are also apparently keen to add a third band to the tour, with Boyz II Men at the top of the wishlist.
A source, who described the possible reunion as the popstar equivalent of current star-studded action movie The Expendables, said: "The idea is to recreate the boyband phenomenon. It will be the ultimate ladies' night out."
The idea was apparently conceived after Backstreet Boys and New Kids On The Block shared the stage during a performance of 'I Want It That Way' in New York this June.
The source added: "The response was amazing. It was a great night of music."
Management reps from both groups are believed to have opened discussions about recording a single together prior to touring, but a Live Nation rep declined to comment.