As deadline looms for Iran nuclear deal, will talks fall apart?
LAUSANNE, Switzerland -- Secretary of State John Kerry's talks with Iran over its nuclear program are intensifying.
The deadline for a preliminary deal is Tuesday, but with just 48 hours to go, negotiators told CBS News that the talks are at risk of failure unless Iran makes significant concessions.
Top diplomats from all the major world powers have flown in to push Iran to take the U.S.-brokered deal.
"If we're going to get this done here over the next few hours, Iran has got to take a deep breath and make some tough decisions," said UK foreign minister Philip Hammond.
But in the way of a deal are two major sticking points:
Iran wants the sanctions that have cut them off from global markets lifted immediately, but the U.S. worries that Iran will then purchase parts that could be used to build a weapon.
And Iran is demanding that they be allowed to further enrich uranium in the final years of a deal, but the U.S. is pushing back.
But even if these hurdles are cleared by the deadline, the administration still needs to convince Congress not to torpedo the deal by rolling out more sanctions.
"I think now's the time to push back from the table and ask ourselves: Is it really time to trust the people that we're negotiation with, the Iranians," said North Carolina Republican Richard Burr.
U.S. officials said it is now or never, and in a nod to the Alps nearby, also said closing the deal is like summiting a mountain peak: the final few feet are the toughest.