Nuclear deal must be right: Obama
President Barack Obama has said the US would "walk away" from nuclear talks with Iran if there is no acceptable deal.
Mr Obama said that any agreement must allow western powers to verify that Tehran is not going to obtain an atomic weapon, and that even if Iran "cheated," the US and others would have "enough time to take action".
The president told CBS's Sunday Morning show that "if we don't have that kind of deal, then we're not going to take it".
Big gaps remain to bridge if the sides are to reach a deal by the end of March deadline set by negotiators. The next round of talks is set to begin on March 15.
Iran says the programme is peaceful and exists only to produce energy for civilian use.