The U.S. Justice Department charged Ali Chawla, a Pakistani national in the Iranian city of Qom; Asim Naqvi, a U.S. national in Houston; and Muzzamil Zaidi, a U.S. national in Qom, with violating the International Emergency Economic Powers Act by moving U.S. currency to Iran at the behest of Iranian Supreme Leader Ali Khamenei. U.S. officials alleged that Chawla, Zaidi, and other members of the group Islamic Pulse received permission from Khamenei to collect a religious tax on his behalf, sending half the money to Iran and half to Yemen. This operation continued after the United States imposed sanctions on Khamenei in 2019. According to the Justice Department, all three defendants "have considerable operational links" to the Islamic Revolutionary Guard Corps (IRGC).

U.S. Secretary of State Mike Pompeo formally notified the United Nations that the United States is seeking the return of all international sanctions on Iran, or "snapback," under the terms of the Joint Comprehensive Plan of Action (JCPOA). According to the JCPOA, any participant to the agreement can notify the U.N. Security Council that Iran is no longer complying with the agreement. If the U.N. Security Council fails to pass a resolution extending sanctions relief within 30 days of such a notification, all previous U.N. sanctions on Iran automatically come back into effect. France, Germany, Iran, Russia, and the United Kingdom argue that the United States lacks the standing to invoke the JCPOA because the United States withdrew from the agreement in 2018. The United States argues that it has the "explicit right" to evoke snapback since the JCPOA was enshrined by U.N. Security Council Resolution 2231. The U.S. move to invoke the full "snapback" of sanctions follows its failure to extend a U.N. arms embargo on Iran.

According to U.S. intelligence agencies, Iran paid bounties to the Taliban for attacking American and coalition troops in Afghanistan at least six times in 2019. The bounties included a payment to the Haqqani network, a Taliban faction, for launching a suicide attack against a U.S. air base at Bagram in December 2019.

The United States seized the cargo of four Venezuela-bound oil tankers alleged to be carrying Iranian petroleum after U.S. prosecutors filed a lawsuit in July seeking permission to intercept the ships. U.S. officials rerouted the ships, the Luna, Pandi, Bering, and Bella, to Houston. The four ships had been traveling with a flotilla escorted by an Iranian naval vessel but split off after U.S. authorities contacted the owners of the vessels. U.S. prosecutors allege that an Iranian businessman tied to the Islamic Revolutionary Guard Corps (IRGC) had arranged the shipments of oil to Venezuela through a series of shell companies. The four ships have ties to companies operated by the Greek businessmen Giorgios and Marios Gialozoglou. Some of these vessels had conducted ship-to-ship transfers, and one of the ships faced allegations of delivering oil to Iranian-backed Houthi rebels in Yemen. In a separate case, a U.S. judge awarded the United States the title to the Grace 1, a ship that U.S. authorities accused of delivering Iranian oil to Syria in 2019.