Iranian President Hassan Rohani is also speaking live on state television at this moment.
Obama: "We have come a long way to reach this point...We should seize it."
AFP: Iran state TV airs Obama's nuclear deal statement live.
OBAMA SAYS IF IRAN VIOLATES THE DEAL, THE SAME OPTIONS AVAILABLE TODAY WILL BE THERE FOR FUTURE U.S. PRESIDENTS
Obama says he will veto any legislation that prevents enactment of the deal.
Obama: "I believe it would be irresponsible to walk away from this deal."
"I welcome a robust debate in Congress on this issue" and scrutiny of the details," he says.
Obama says "no deal means a greater chance of more war in the Middle East."
Obama asks lawmakers to consider a world without this deal. "We put sanctions in place to get a diplomatic resolution, and that is what we have done."
"No deal means no lasting constraints on Iran's nuclear program," Obama says.
Obama says the IAEA will have access to suspect sites "where necessary, when necessary."
He says sanctions relief will be phased in, that Iran must first complete key steps.
Obama says the deal is not built on trust, but on verification by inspectors.