WASHINGTON: The United States said Monday that a deal was possible at Iran nuclear talks in Vienna, but that an agreement had to be completed urgently as Tehran advances its nuclear capabilities.

Iran nuclear deal talks to resume in Vienna on Tuesday: EU

"A deal that addresses all sides' core concerns is in sight, but if it is not reached in the coming weeks, Iran's ongoing nuclear advances will make it impossible for us to return to the JCPOA," a State Department spokesperson said, refering to the 2015 framework agreement.