It had been thought that talks aimed at bringing the Slovakian to the club on a permanent deal had stalled, but Williams says they are on-going and the deal is not dead.
“Although the deal did hit the rocks, as it were, it’s certainly not dead," Williams told the clubs official website.
"We are still in negotiations with Gresko and with Parma.
"For the moment, let’s just say, we are still talking.”
The 26-year-old left back impressed while on loan from FC Parma and manager Graeme Souness is keen to sign the defender on a permanent deal.