A senior US official at nuclear talks with Iran says negotiations could go beyond Tuesday's deadline for the outline of an agreement.
The official said work on the outline will go on "if we are continuing to make progress, including into tomorrow, if it's useful to do so."
The official spoke on condition of anonymity because the official wasn't authorized to discuss the talks by name.
Six world powers and Iran faced a deadline today for a framework agreement on controlling Iran's nuclear ambitions. A final deadline is June 30.
