Economists had predicted more than $1 trillion of international investment would flow into Iran over the next decade. But even before the latest US decision, the money had been slower to materialise than anticipated.
After a nuclear deal was agreed between Iran and a group of major world powers and sanctions were lifted in 2015, entrepreneurs and many foreign investors launched businesses in the country.
Although Iran's economic recovery has not been as fast as expected, many companies like Total, Peugeout Citroen, Boeing and Airbus made investments in the country.
These investments would be in jeopardy if the United States withdraws from the nuclear agreement and imposes more sanctions.
TRT World's Sarah Morice reports from London, UK.