Iran trumpeted advances in nuclear technology, citing new uranium enrichment centrifuges and domestically made reactor fuel, in a move abetting a drift towards confrontation with the West over its disputed atomic ambitions.
The announcement underlined Iranian determination to pursue a nuclear programme its Islamic clerical rulers see as a pillar of power, protection and prestige despite Western sanctions that are inflicting increasing damage on Iran's oil-based economy.
Iran has been resorting to barter to import basic staples as sanctions, imposed over its pursuit of nuclear activity seen in the West as geared to developing atomic bombs, have spread to block its oil exports and central bank financing of trade.
Tehran has for some years been developing and testing new generations of centrifuges to replace an outdated, breakdown-prone model. In January it said it had successfully manufactured and tested its own fuel rods for use in nuclear power plants.
The aim of its announcements was to show that international sanctions are failing to stop it making progress in nuclear know-how despite trade embargoes and to strengthen its hand in any renewed negotiations with six world powers.
Western analysts were sceptical of the proclaimed advances.
"We have seen this before. We have seen these announcements and these grand unveilings and it turns out that there was less there than meets the eye. I suspect this is the same case," said Shannon Kile at the Stockholm International Peace Research Institute (SIPRI).
