The activity at one of the country's chief nuclear plants signals Tehran is in defiant mood ahead of the resumption of talks over its nuclear programme, set to resume next week.
Washington has described the move, if confirmed, as "another provocative step".
"We hope that the Iranian regime will make the strategi
c decision to come to the February 26 talks, with the P-5-plus- 1 in Kazakhstan prepared to discuss substance so there can be progress in addressing the international community's concerns about the nature of the Iranian nuclear programme," said White House spokesman, Jay Carney.
Western powers fear Iran is seeking weapons technology as it speeds up its uranium enriching capacity. Tehran insists its objectives are for peaceful energy purposes.
Source: Euronews
