Newcastle have reportedly been informed by Lyon that they must up their initial offer for Aly Cissokho if they hope to sign him before the transfer deadline.
According to talkSPORT, the Ligue 1 outfit rebuffed a bid in the region of £7 million and are unwilling to accept less than their £10 million valuation of the France international.
The 23-year-old left-back is said to have been identified by Newcastle as a potential replacement for Jose Enrique, who left St James' Park for Liverpool earlier this month.
Cissokho would certainly been an able successor to Enrique, with the defender performing consistently for Lyon since his transfer to the Stade de Gerland in 2009.
Newcastle, meanwhile, are also understood to be pursuing Erik Pieters of PSV Eindhoven in the hopes of permanently filling the left-back position.
Newcastle have made a bid for Holland international, although Alan Pardew says the two clubs are currently at an impasse over the valuation of the player.
"I think there is a little of brinkmanship going on and I think that's understandable," said the Toon boss.
"If clubs are resigned to losing a player they want the best possible price so when a transfer becomes close, suddenly a lot of other clubs and the press seem to know about it."