Iran is ramping up the rate at which it enriches uranium several months after receiving a $6 billion transfer from the Biden administration, according to the International Atomic Energy Agency (IAEA).

Iran had slowed down its uranium enrichment program in June, a move that diplomats believe was related to negotiations with the Biden administration that ultimately led to the unfreezing of $6 billion in oil assets to Tehran, Reuters reported. Iran is now reversing the slowdown and has begun ramping up its uranium enrichment process once again, the IAEA said in a new confidential report this week, according to Reuters. 

Since June, Iran had been enriching uranium at a rate of roughly 3 kg a month, but as of November that number had tripled, according to the IAEA’s report viewed by Reuters.