Total's departure comes as a huge blow to Iran and is the first major energy scheme to be scuppered by USA sanctions. Insurers, which are mainly USA - or European-based, have begun winding down their Iranian business to comply with the sanctions.
"We want the United States to implement that (2015) nuclear deal" Foreign Minister Mohammad Javad Zarif told CNN on Sunday.
However, when the United States announced that it would restore sanctions against Iran, the French major said it would withdraw from Phase 11 to avoid American punitive measures.
Iran's Petroleum Minister Bijan Zanganeh says French energy giant Total has officially left the country, ending speculations over whether it would stay to finish a gas project following the return of United States sanctions against the Islamic Republic.
The United States also imposed fresh sanctions on Tehran in August, targeting Iran's trade in gold and other precious metals, its auto industry, and purchases of US currency.
Zangeneh said a "process" was under way to replace Total with another company. Iranian officials have repeatedly rejected the offer.
The energy firm's departure was announced by Iran's oil minister who reportedly told state media the company is leaving in response to threats from Washington to sanction companies that do business with the Islamic republic.
To safeguard their supplies, state oil trader Zhuhai Zhenrong Corp and Sinopec Group, Asia's biggest refiner, have activated a clause in long-term supply agreements with National Iranian Oil Corp (NIOC) that allows them to use NITC-operated tankers, four sources with direct knowledge of the matter said.
Trump signed an executive order on August 6 reimposing the first round of sanctions on Iran, which had been lifted under the nuclear deal, to levy "maximum economic pressure" on the Islamic Republic.
In July, all 17 tankers chartered to carry oil from Iran to China were operated by NITC, according to shipping data on Thomson Reuters Eikon.
NIOC did not respond to an email seeking comment.
It was not immediately clear how Iran would provide insurance for the Chinese oil purchases, worth some $1.5 billion a month.