VIENNA (Reuters) - Iran will never slow down its nuclear research programme, its supreme leader said on Wednesday as negotiators from Tehran and six world powers struggled to narrow "significant gaps" that the United States warned might be insurmountable.
The stakes in a deal are high on both sides. Western powers, along with Russia and China, want to prevent chronic tensions in the Middle East from boiling over into a wider war or triggering a regional nuclear arms race. Iran, for its part, is keen to be rid of international sanctions hobbling its oil-based economy.