The South Americans booked their place in the second round of the tournament on Saturday with a narrow 1-0 victory over Iran.
While admitting that the squad is determined to do well in Brazil, Romero is wary of talking up his side's hopes of lifting the trophy.
"Our aim is to be here for 30 days, but we're not going to talk about the title," he told FIFA.com.
"The fans should know that we're going to keep on giving everything we have. We're not even easing off in the training sessions. Nobody wants to miss them, which is a really good sign."
Argentina continue their Group F campaign on Wednesday when they play Nigeria.