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.

With thousands of advanced centrifuges on standby, Tehran says it is now spinning more, which could increase its stockpile of near-bomb-grade atomic fuel.

Iran said it will increase the number of centrifuges in its nuclear program in response to a censure by the United Nations’ nuclear watchdog, ratcheting up tensions with the West just days after it signaled a willingness to ease them.