The Manchester City boss was eager to bring Mbappe to the Etihad Stadium but Paris Saint-Germain were able to secure his services on a season-long loan deal.
Guardiola previously enjoyed a successful spell with the Blaugrana, working alongside superstar Messi, who the Spaniard maintains is the best player in the world despite Mbappe's rise in the game.
He said: “Nobody can sit at the same table as Messi. Maybe Mbappe, he’s a top player, he will be an outstanding player, I’m pretty sure of that.
“But to equal what Messi has done in 10 or 12 years, or Cristiano (Ronaldo), for example, we have to wait. I appreciate Mbappe wouldn’t like me to put more pressure on his shoulders.”