West Ham will sell Issa Diop, who is being monitored by Manchester United, for £60m a source close to the player has told Sky Sports News.
United are interested in signing the centre-back and a £45m plus a player bid has been discussed.
The Hammers want a United player as part of a potential deal, but the Old Trafford club are not willing to give their Premier League rivals the player they have targeted.
Listen to the latest episode of the Transfer Talk podcast: What is Pogba worth?
Sources close to Diop say PSG and Barcelona have been watching him, while he has been told to be ready for a call-up to the France squad.
West Ham are adamant Diop is not for sale and it is believed they would not even listen to offers of less than £60m for a player who has four years left on his contract and who may be rewarded with an improved deal.
Diop is happy at West Ham, but would like to play in the Champions League in the future, Sky Sports News understands.
He featured 38 times last season after joining from Toulouse for £22m and helped West Ham secure a 10th-place finish.