The Catalan outfit have been locked in talks as they bid to persuade the midfield playmaker to commit his future to the club as rumours abound that he could leave.
Premier League champions Manchester United have been strongly linked with Iniesta as they could offer him a new adventure, but Barcelona believe that they will stave off any interest from other clubs.
"We are close to agreeing a new contract with Iniesta," sporting director Andoni Zubizarreta told Radio Catalunya.
"I think it could happen before Christmas."
Meanwhile, Zubizarreta has reflected on Barcelona's search to find a replacement for the departing Victor Valdes and explained that the club may look to strengthen their position with more than one keeper.
Valdes announced that he will leave the Blaugrana at the end of the current campaign and reports in Spain suggest Borussia Monchengladbach's Marc-Andre ter Stegen is top of their list.
Zubizarreta added: "I do not want to name names. People talk, but all they know is that I travelled to Germany, not what I did there.
"There is a lot to chew over and we cannot rule out signing not just one, but two goalkeepers."