The Hammers have been in talks with Juventus for several weeks in their pursuit of the Swiss midfielder this summer.
A deal was close to getting agreed upon between the clubs but Juventus demanded more money once Cristiano Giuntoli became their new sporting director earlier this month.
Since then the two clubs have been involved in protracted negotiations and no agreement is in sight, with other sides also taking an interest, including Aston Villa, who have enquired.
Giuntoli has been trying to get other clubs into the race but, according to Italian outlet Calciomercato.com, West Ham remain Zakaria’s priority this summer.
French club Lens have been involved in talks with Juventus and RB Leipzig and Bayer Leverkusen have also made enquiries.
But the Hammers remain in pole position as the talks between the two clubs continue to drag on.
Zakaria is not part of Juventus plans but the Serie A giants do not want to lose him for a cut-price fee.
They are insisting on including an obligatory purchase clause in any loan, which West Ham are yet to agree to.
