Doha$6 billion in frozen funds is the sticking point.
Iran wants its Qatari-held assets released in two tranches; Washington has proposed restricting the money to US agricultural purchases, which Tehran rejects.
Iranian and US technical teams meet again through Qatari and Pakistani mediators with no date set for direct talks.
Sources: Al Jazeera Online, The Times of Israel, Aol, NDTV, Yahoo News