The Ligue 1 side announced on Thursday night that the 22-year-old Frenchman would soon be signing a five-and-a-half-year contract with the Magpies for around £1.8m.
"Newcastle are a very good club, despite the fact that they are fairly low down in the standings at the moment," Sissoko told the club's official website. "They have quality players and had a brilliant season last year.
"I will get game time at Newcastle, and it is important for me as a player to play as much football as possible. I think Newcastle is the ideal club."
Once the move is finalised, Sissoko will be the fifth French player to join Newcastle during the January transfer window.