Iran's International Atomic Energy Agency (IAEA) ambassador Ali Asghar Soltaniyeh briefs the media after a meeting on the Iranian nuclear issue in Vienna with EU, Russian and U.S. diplomats at Vienna's UN headquarters October 21, 2009. REUTERS/Herwig Prammer

TEHRAN (Reuters) - Iran declined on Friday to endorse proposals by the U.N. nuclear watchdog to help reduce Iran’s stockpile of low-enriched uranium.

It said it was awaiting a “positive and constructive” response from world powers to its proposal on providing nuclear fuel for a Tehran reactor producing medical isotopes, state television reported.

“Now we are awaiting a positive and constructive response on Iran’s proposal from the other party on providing nuclear fuel for Tehran’s reactor,” TV quoted a member of Iran’s negotiating team, who attended the Vienna meeting on October 21, as saying.

“The other party is expected to avoid past mistakes in violating agreements ... and to gain Iran’s trust,” the unnamed official said.

The U.N. nuclear watchdog on Wednesday presented a draft deal to Iran and three world powers for approval within two days to reduce Tehran’s stockpile of low-enriched uranium, seen by the West as a nuclear weapons risk.

The three powers -- Russia, the United States and France -- have all signaled approval of the draft.

Western diplomats said the plan would require Tehran to send 1.2 tons of its known 1.5-tonne reserve of low-enriched uranium (LEU) to Russia and France by the end of the year.

The material would be converted into fuel for the Tehran medical reactor.