Perisic has been heavily linked with a move to Premier League giants United, though a deal is yet to materialise.
Inter have insisted the Perisic will remain in Milan and Ausilio reiterated the Serie A club's stance regarding the Croatia international winger and team-mate Antonio Candreva, who is reportedly a target for Chelsea.
"I don't understand where some of these stories come from," Ausilio told Mediaset Premium.
"Candreva has never been on the market and we have absolutely no intention of selling him.
"The same goes for Perisic, who is an important player and we are currently discussing a new contract with him."
Inter have been active in the transfer market, signing Matias Vecino, Milan Skriniar and Borja Valero, while Nice full-back Dalbert is set to arrive.
The Italians have also been linked with Bayern Munich star Arturo Vidal, but Ausilio said: "We realised straight away that it was practically impossible to get Vidal, because when Bayern don't open the door, you’ve got no chance."