Iran announced Friday it was activating new advanced centrifuges – which enrich uranium for the country’s nuclear program – after the United Nations’ nuclear watchdog criticized the country for not cooperating with the agency.

The U.N. nuclear watchdog’s board has condemned Iran for failing to cooperate fully with the agency, the second time it has done so in just five months.

The resolution comes after the agency said Iran has defied demands to rein in its nuclear program and has increased its stockpile of uranium enriched to near weapons-grade levels.