The 25-year-old Frenchman recently claimed that he is eager to hold talks with the Premier League club.
"Fulham are genuinely interested in Sako and now it is about negotiations between the two clubs," Jackett told the Birmingham Mail.
"As far as I know no fee has been agreed yet, but they are in negotiations. I don't know if it is close.
"The offer's at a very high level, whether it is at a point where the powers that be at Wolves want to accept that or not is another matter."
Sako has two years left on his contract at Molineux.