Iniesta scored in Saturday's Copa del Rey final triumph over Sevilla.
"This week I will announce my decision, I think it is clear but what we are happy about here is what has happened today. I really wanted today to go well and it did do so from the first minute," he said.
"It was a great night in all senses, collectively and personal. It is a title that what we wanted to win and we will try and add the league.
"The team and the fans deserve a ten. There are a lot of emotions and feelings. I am happy for this display and more than anything for the title. Everyone was thinking in Roma but we deserved this."