Speaking during a daily news briefing, White House spokesperson Jay Carney said that "it's possible, but it has always been possible", to have direct conversations with Iran, if "they are serious about ridding themselves of their nuclear weapons programme and honouring the international commitments that they've made".
But Carney said they "have no meetings scheduled," as both Obama and Rouhani are expected to attend UN General Assembly next week.
Before leaving for New York for the UN appearance, the Iranian president said Wednesday during an interview with NBC, a US TV network, that his administration would never develop nuclear weapons and that he had full authority to make a deal with Western powers on his country's atomic programme.
Carney said that the Obama administration obviously noticed a significant change in language and tone from the new Iranian government when compared to its predecessor.
The spokesperson, however, also added that the US won't just take Iran's words for it, as "actions are more important than words".
On the same day, US Secretary of State John Kerry also said that Rouhani's comments are "very positive", but "everything needs to be put to the test".