The Treasury move, first reported by Reuters, comes days before US President Donald Trump plans to travel to China for a meeting with President Xi Jinping and as efforts to end the war with Iran have stalled.

In a statement, Treasury said it remains ready to take economic action against Iran’s military industrial base so Tehran cannot reconstitute its production capacity and project power outside its borders.

Treasury said it was also prepared to act against any foreign company supporting illicit Iranian commerce, including airlines, and could impose secondary sanctions on foreign financial institutions that aid Iran’s efforts, including those connected to China’s independent “teapot” oil refineries.

“Under President Trump’s decisive leadership, we will continue to act to Keep America Safe and target foreign individuals and companies providing Iran’s military with weapons for use against US forces,” Treasury Secretary Scott Bessent said in a statement.