Total is at risk of losing its stake in the Iranian South Pars gas field if it exits the country due to US sanctions, Iran’s state-owned oil company has said, according to Bloomberg.

Ali Kardor, managing director of the National Iranian Oil Company (NIOC), said that Iran would transfer the French oil company’s controlling 50.1% share to China National Petroleum Corporation (CNPC), which currently owns 30%.

Kardor did not say whether Total would be compensated if it pulled out of South Pars, the world’s largest natural gas deposit.

The warning comes ahead of an announcement by US President Donald Trump over whether the US will exit the Iran nuclear deal and restore economic sanctions.

The president could choose to enforce a blanket ban on multinational companies doing business in Iran. This would jeopardize Total’s interest in South Pars, into which it has so far invested $90 million.

The company argues that it came to an agreement with Iran after sanctions were relaxed following the signing of the 2015 nuclear accord, according to the Wall Street Journal.

“Total has been and will continue to be particularly vigilant about developing this gas project in strict compliance with all applicable national and international laws,” the company stated.