This week, the joint commission of the Joint Comprehensive Plan of Action (JCPOA) — that is, the remaining parties to the Iran nuclear deal (Iran, the European Union, Russia and China) — agreed that the United States could not initiate "snapback" sanctions on Iran because the Trump administration withdrew from the deal in May 2018.
The decision of the JCPOA signatories as well as the UN Security Council was a rebuke to US diplomacy on Iran.