The 25-year old Frenchman, who arrived at the Molineux from Saint-Etienne in August last year, is keen on playing in the Premier League and hopes the Cottagers' interest can turn into a permanent move to Southwest London.
"When I joined Wolves, the club said to me the aim was to reach the Premier League together," Sako told Sky Sports.
"I am sad that has not happened, but I gave everything and have always been respectful to the club.
"At that first meeting, I sat with [the former Wolves manager] Stale Solbakken and Jez Moxey and they told me if we didn't get promoted, the club would let me go.
"I was told I could speak to Fulham and now I don't understand the delay. I would like things to be sorted out. I am only being ambitious. I believe the fans will understand that."