Bristol's Liberal Democrat-run City Council has already approved the planning application for the stadium, but following an application by residents, an independent planner recommended the area be registered as a town green, preventing new development.
A club statement read: "The club understands the mediation between landowners and applicants in respect of the application to register the site of the planned regional stadium at Ashton Vale as a Village Green has concluded without an agreement being reached to the satisfaction of all parties.
"This is naturally very disappointing news. The club cannot comment further at this stage on the detail of the discussion as it has not been involved at any stage in the mediation process.
"We remain as determined as ever to deliver the regional stadium the city deserves and the vast majority of Bristolians support.
"A huge amount of effort has gone in to get to this point, with the result that we have the finance, political support and planning permission to build the stadium and we remain utterly committed to bring the vision and plans for a new regional stadium for Bristol to reality as soon as possible."
Source: PA
Source: PA