By Parisa Hafezi DUBAI (Reuters) -Fresh talks between Iranian and U.S. negotiators to resolve disputes over Tehran's nuclear programme ended in Oman on Sunday with further negotiations planned, officials said,

Tehran called Sunday’s meeting “difficult but useful” as the two sides clash over future of Iran’s uranium enrichment.

Iran described the latest meeting as "difficult but useful," while a senior U.S. official, speaking to AFP on condition of anonymity, said Washington was "encouraged by today's outcome and look forward to our next meeting,