Iran said on Monday efforts to revive a 2015 nuclear deal could succeed if the United States took a political decision to meet Tehran's remaining demands, as months of negotiations enter what one Iranian diplomat called a "now or never" stage.
The stakes are high, since the failure of 10 months of talks could carry the risk of a fresh regional war, of more harsh sanctions on Iran by the West and of continued upward pressure on world oil prices already strained by the Ukraine conflict.
