Ali Akbar Velayati, the foreign policy adviser to Iranian Supreme Leader Ayatollah Ali Khamenei, has outlined a number of steps Iran can take to strengthen its nuclear program in the face of the US exit from the three-year-old deal in which Iran reduced its nuclear activities in exchange for sanctions relief.
Velayati's first recommendation was to make operational UF6 (uranium hexafluoride), which is a compound used in uranium enrichment. Asghar Zarean, the deputy head of the Atomic Energy Organization of Iran, had previously discussed testing the use of UF6 into more modern IR8 centrifuge machines under the supervision of the International Atomic Energy Agency (IAEA). UF6 is a feedstock for centrifuges. After uranium is mined and processed into yellowcake, it is turned into gas and injected into centrifuges in the form of UF6.