The US State Department announced that it is ending the waiver for JCPOA-originating nuclear projects in Iran: the Arak reactor conversion, the provision of enriched uranium for the Tehran Research Reactor, and the export of Iran’s spent and scrap research reactor fuel. 

OFAC issued FAQ 829 regarding the announcement clarifying that persons engaged in activities associated with the Arak reactor modernisation redesign, the transfer into Iran of enriched uranium for the Tehran Research Reactor, and the transfer out of Iran of certain nuclear fuel scrap and of spent research reactor fuel will have a final, 60-day wind-down period to cease the activity. The 60-day period ends on 27 July 2020. 

Persons engaged in such activity should ensure they wind-down operations or risk exposure to US sanctions.

Secretary of State Mike Pompeo announced that the US is, however, providing a 90-day extension for the waiver covering ongoing international support to the Bushehr Nuclear Power Plant Unit 1 to ensure safety of operations. But the US will "closely monitor" developments and may modify the waiver at any time. 

The US is also adding names of individuals responsible for overseeing Iran's nuclear progamme to the specially designated nationals list.