The French winger is looking for a move to Craven Cottage after claiming he was promised the club would let him go if they were not promoted from the Championship in 2013
The French midfielder signed for Wolves from Ligue 1 side St Etienne last summer, and made 37 appearances in the Championship, scoring nine goals for the relegated side.
Sako revealed that any move to the Cottagers would depend on chief executive Jez Moxey reaching an agreement with his counterpart Alastair Mackintosh.
"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."
Wolves were relegated to League One after finishing just one spot above bottom side Bristol City, despite only being relegated to the Championship in 2012.
Sako added: “In the difficult moments we had last season, [the fans] were very good to me and I hope they saw someone who gave everything back to them. I will never speak badly of the supporters."