Iran claims to have enriched 6.5 kilograms (14 pounds) of uranium to 60% purity, a government spokesperson said on Tuesday, in an apparent bid to dial up the pressure on world powers that are renegotiating the landmark nuclear agreement. 

Cabinet spokesperson Ali Rabiei also said Iranian scientists had further violated the nuclear deal by increasing the stockpile of 20% enriched uranium to 108 kilograms (238 pounds), up from 90 kilograms (198 pounds) last month. 

The 2015 nuclear deal, known as the Joint Comprehensive Plan of Action (JCPOA), set curbs on the purity and amount of Iran’s enriched uranium stockpile. In return for placing limits on its nuclear program and allowing international inspections of its nuclear sites, Iran was granted relief from crippling economic sanctions.

The signatories to the deal estimated it would take Iran at least a year to amass enough fissile material to develop a nuclear weapon in the event that Tehran reneged on the agreement. That so-called breakout time to build a bomb has dropped to a matter of months, Secretary of State Antony Blinken said last week.