In November 2013, Tehran and a group of diplomats from five permanent UN Security Council members plus Germany, or P5+1, agreed to reach a long-term agreement. Under the deal, Iran must guarantee peaceful character of its nuclear program in exchange for partial lifting of sanctions by the international community.
"The good news is that during this period [since November 2013] Iran has abided by the terms of the agreement. We know what's happening on the ground in Iran. They have not advanced their nuclear program," Obama said.
The US President also stressed that Washington would exit the negotiations process if the deal was not reached.
"If there's no deal then we walk away. If we cannot verify that they are not going to obtain a nuclear weapon… if we don't have that kind of deal, then we're not going to take it," Obama said.
For years the West has been suspecting Iran of developing nuclear weapons under the guise of a civilian program — claims that Tehran has strongly denied.
Negotiators have set the current deadline for concluding a long-term comprehensive deal for July, 2015.
