Monaco are in talks with 18-year-old France striker Kylian Mbappe over a contract extension, says vice-president Vadim Vasilyev.
Mbappe, who is under contract until June 2019, has been strongly linked with a move to Real Madrid.
Manchester City have also been linked, but BBC Sport understands they are reluctant to pay the reported 180m euro (£160m) asking price.
Vasilyev said the Ligue 1 club Monaco have had several "serious" enquiries.
But he added: "We are in discussions over a contract extension with Kylian and we hope to reach an agreement."
Mbappe, who has won four caps for France, scored 26 goals in all competitions for Monaco last season.
Earlier in July, Monaco said "important European clubs" had made contact with the player without their permission.
Monaco may ask world governing body Fifa and the French league to consider disciplinary action, but Fifa said it has not received a complaint.
BBC Sport understands Manchester City are the only English club accused.
"We haven't reached an agreement with any club for Mbappe," Vasilyev said.
"We are negotiating to extend his contract but you mustn't push the player too hard. We must allow him to take his time, not rush things.
"There is too much media pressure. I remind you he's only 18."
Vasilyev also described Thomas Lemar, a key target for Arsenal, and Fabinho, who has been linked with Manchester United, as "essential" players who are "staying with us".