WASHINGTON (AP):

President Barack Obama says he has a personal stake on ensuring that negotiations with Iran produce an agreement that keeps Tehran from producing a nuclear weapon over the long-term.

He says in an interview with The Atlantic that if Iran has a nuclear weapon in 20 years he would be held accountable.

"Look, 20 years from now, I'm still going to be around, God willing. If Iran has a nuclear weapon, it's my name on this," he said. "I think it's fair to say that in addition to our profound national security interests, I have a personal interest in locking this down."

Critics of an agreement say the president is so determined to burnish his legacy that he will accept a less-than-ironclad commitment from Iran. The talks involve Iran, the US, four other permanent members of the UN Security Council and Germany - a group call the P-Five Plus One. Israel and some Persian Gulf allies worry that Iran may simply be delaying its ability to build a nuclear weapon in order to have economic sanctions against it lifted.

But Obama and his aides say his investment in the talks and a realisation that it could in fact damage his legacy is why he will pursue a strong and enforceable agreement.

"He's not going to sign a bad deal precisely because it's his name that's on it," White House spokesman Josh Earnest said yesterday when asked about Obama's response.

The Atlantic interview covered a range of Middle East issues, from US-Israel relations to Iran to the status of the fight against the Islamic State. The interview occurred before the takeover of the city of Palmyra by Islamic State militants, but after the city of Ramadi in Iraq fell to Islamic State fighters.

Obama called the loss of Ramadi a "source of concern," but added: "I don't think we're losing."

"There's no doubt there was a tactical setback, although Ramadi had been vulnerable for a very long time, primarily because these are not Iraqi security forces that we have trained or reinforced," he said.