Meanwhile, state broadcaster IRIB reported that Iran was also shifting its higher grade uranium enrichment work from a site it has used for years to Fordo and aims to triple the production capacity of the nuclear fuel.

“This year, under the supervision of the [International Atomic Energy] Agency, we will transfer 20 percent enrichment from the Natanz site to the Fordo site and we will increase the production capacity by three times,” the head of Iran’s atomic energy agency, Fereydoun Abbasi-Davani, told reporters after a cabinet meeting, IRIB reported.

The statement is another act of defiance by Iran, slammed with international sanctions over its controversial nuclear program.