EXCLUSIVE

Birdman and Lil Wayne have officially declared war ... settlement talks have broken down and Wayne will now sue his mentor, claiming among other things Birdman owes him $8 million.

As TMZ reported ... the 2 titans tried coming to terms this week but it wasn't meant to be. Now Wayne will ask a judge to declare him free of Cash Money and Birdman's control. Wayne says Birdman has violated their contract by withholding the release of his new album.

As for the $8 MIL claim ... Wayne says Birdman owed the money for his latest album -- it was supposed to be an advance.

Birdman has held firm ... he will release the album "in due time," but clearly that's not good enough for Wayne.