The US vice president has rejected calls for more sanctions against Iran over the Islamic Republic's nuclear energy program, PressTV reported.
"This is not the time to risk a breakdown when we still have a chance for a breakthrough," Joe Biden said on Saturday, speaking at a forum on the Middle East at the Brookings Institution think tank.
"I tell you, I think it's a less than even shot but it's a shot, nonetheless," he noted.
Biden's comments come as the US Senate is pushing for fresh punitive measures against Tehran. US President Barack Obama has threatened to veto any new sanction legislation.
Last November, Iran and the P5+1 group -- France, Britain, the US, Russia and China, plus Germany -- clinched an interim nuclear accord that took effect on January 20 and expired six months later. However, they agreed to extend their talks until November 24 as they remained divided on a number of key issues.
On November 24, the two sides wrapped up a week of intense closed-door nuclear negotiations in the Austrian capital of Vienna. The talks aimed to tackle the remaining obstacles that exist in the way of reaching a final agreement.
At the end of the talks, the two sides decided to extend their discussions for seven more months. They also agreed that the interim deal remain in place during the remainder of the negotiations until July 1, 2015.