The Spanish midfielder believes that Barca can still finish the league at the top of the table, while noting that Madrid will have a hard task against Atletico
Tuesday's 4-0 thrashing of Getafe has seen the Catalan outfit provisionally move just one point shy of leaders Real Madrid ahead of Los Blancos' derby against Atletico Madrid on Wednesday.
One month ago, Barca found themselves 10 points behind Madrid, and Iniesta says that anything can happen before the end of the season.
"Madrid are still the leaders," Iniesta told reporters. "They have the advantage and a game in hand.
"Things have changed, but we will keep fighting to add three points with every game. That is what we want until the end.
"Madrid can win matches like the one on Wednesday. But these derbies are always very intense."
Barca will travel to Levante on Saturday in their upcoming La Liga fixture.