Everton have put in a £7.1m bid for Gueye and will now be able to discuss personal terms with the player.
Gueye is also attracting interest from France, and Everton may face stiff competition for the midfielder.
However, the recently relegated side do not want to sell the player and will do all they can to convince Gueye to stay.
The 26-year-old played 38 times for Villa last season, scoring one goal.