Iran wants more talks on a U.N.-drafted nuclear deal and to import atomic fuel rather than send its own uranium abroad for processing, a Iranian diplomat said, suggesting terms world powers are likely to rebuff.

Western powers have urged Iran to accept a draft deal in which it would send most of its low-enriched uranium (LEU) abroad by the end of the year for further enrichment to turn it into fuel for a medical reactor in Tehran.

But Iranian Ambassador Ali Asghar Soltanieh told Reuters on Monday that more talks were needed "in order to ensure that our technical concerns, and especially the issue of the guarantee of the fuel supply, are taken into consideration."

Iran''s requests will add to doubts that a way out of a standoff with big powers will be found soon.

U.S. Secretary of State Hillary Clinton urged Iran to accept the draft proposals. "We urge Iran to accept the agreement as proposed. We are not changing it," she told a news conference in Marrakesh, adding this was a "pivotal moment" for Tehran.