Asserting that “gaps” still exist in negotiations over Iran’s controversial nuclear programme, President Barack Obama has said the U.S. is prepared to “walk away” if a deal cannot be made with Tehran to verify that it is not going to obtain an atomic weapon.

“If there’s no deal, then we walk away,” Mr. Obama told CBS News in an interview.

“If we cannot verify that they are not going to obtain a nuclear weapon, that there’s a breakout period, so that even if they cheated we would be able to have enough time to take action, if we don’t have that kind of deal, then we’re not going to take it,” he said.

Responding to questions, Mr. Obama said there is enormous suspicion between the Iranian regime and the world, not just the U.S.

“The Iranians have negotiated seriously because we were able to bring them to the table through some of the toughest sanctions that have been ever put in place. We have made progress in narrowing the gaps, but those gaps still exist,” he said.

“I would say that over the next month or so, we’re going to be able to determine whether or not their system is able to accept what would be an extraordinarily reasonable deal, if in fact, as they say, they are only interested in peaceful nuclear programmes,” Mr. Obama said.

“If we have unprecedented transparency in that system, if we are able to verify that in fact they are not developing weapon systems, then there’s deal to be had. But that’s going to require them to accept the kind of verification and constraints on their programme that, so far at least, they have not been willing to say yes to,” the U.S. President said.

Mr. Obama said it is fair to state that there is urgency because the two sides have now been negotiating for well over a year.

“The good news is, is that during this period Iran has abided by the terms of the agreement, we know what is happening on the ground in Iraq. They have not advanced their nuclear programme. We have been able to roll back their 20 per cent highly enriched uranium during this period of time. It’s given us unprecedented access into what they are doing. So we’re not losing anything through these talks,” Mr. Obama said.