A senior U.S official in Vienna said negotiators will not make tomorrow's deadline on an agreement on Iran's nuclear program, NBC News reported. And while those involved in the talks are willing to spend a few more days hammering out details, no one will agree to a long term extension. They are also not willing to renegotiate what they say Iran agreed to in April to reduce its weapon-making ability. Iran's Foreign Minister Zarif returned to Tehran last night for consultations and is expected back in Vienna tomorrow, the day the negotiators were supposed to complete a final agreement. "We are still focused on completing a comprehensive agreement in this round," the senior U.S official said. "No one is talking about a long-term extension."