US banks provide more than 90 percent of Total's financing, the French firm said. The company also noted that American investors represent more than 30 percent of Total's shareholders. Moreover, Total has invested more than US$10 billion in US assets.
Elizabeth Rosenberg, a senior fellow at the Center for a New American Security and former Treasury official, said that Total's request for a license to continue the project was a "brave" push for leniency from Trump.
"This is about as aggressive as any publicly traded company could be in demonstrating support for Iran," she said. "Total has quite a flair for diplomacy. I took it as being a forward-leaning statement that it is interested in pursuing its project."
Total has spent less than US$48 million on the project so far. The company said pulling out of Iran would not affect its production growth targets through 2022.
Iran holds the second-biggest natural gas reserves in the world, trailing Russia. And Iran "harbours ambitions of becoming a significant gas and [liquefied natural gas] LNG exporter in the coming years," S & P Global Platts said in a note to investors.
Iran already exports small volumes of gas - around 1.4 billion cubic feet a day - to Turkey, Iraq and Turkmenistan.
S & P Global Platts estimated that Total's South Pars project was to produce 2 billion cubic feet a day, mostly for the domestic market.
The French company holds a 50.1 per cent interest in the South Pars project. The Chinese National Petroleum Corp. holds 30 percent and the National Iranian Oil Co. subsidiary Petropars holds 19.9 per cent.
It remains unclear whether Total will attempt to sell its share of the South Pars group and whether CNPC might risk buying it up despite sanctions in the United States.