Nanab Berries and Pinap Berries are also now available in the game.
The update includes Pokémon from the Johto region in the Pokémon Gold and Pokémon Silver games.
Nanab Berries slow Pokémon movements to make them easier to catch, while Pinap Berries double the number of Candies players receive after a successful capture.
The official Twitter account for the Pokémon franchise announced on Thursday that the update for the Pokémon Go smartphone game that is releasing 80 new Generation 2 Pokémon for the game is now live.