"Iran uses its oil revenues for funding proxy wars and terrorism. The United States is working with allies and partners to deprive the regime of their funds. We are very pleased that so many companies and countries are moving forward to stop awarding Iranian oil," Fannon said during his address at the Oil & Money conference in London.
However, Fannon declined to speak to journalists after his address to elaborate on this statement.
In September, the remaining parties to the nuclear deal said they had agreed to work on special payment channels to facilitate trade with Iran, such as EU-proposed Special Purpose Vehicle (SPV).
READ MORE: Iran Devises Plan to Keep Oil Trade as 2nd Wave of US Sanctions Nears — Reports
After the United States announced its withdrawal, other participants of the deal, including Iran itself, China, Germany, France, Russia, the United Kingdom and the European Union, reaffirmed their commitment to the agreement.