Tehran sold an average of 1.56mn barrels a day during the first three months of the year, almost all of it to China and its highest level since the third quarter of 2018, according to data company Vortexa.

Iran’s success in exporting its crude underscores the difficulties facing the US and the EU as they seek to build up pressure on Tehran, the Financial Times reported.

“The Iranians have mastered the art of sanctions circumvention,” said Fernando Ferreira, head of geopolitical risk service at the Rapidan Energy Group in the US.

In Tehran, Tasnim News Agency said on Wednesday that the country’s oil industry had found ways to get around sanctions.

Iran’s Oil Minister Javad Owji said last month that oil exports had “generated more than $35bn” in the preceding year. On another occasion, he said that while Iran’s enemies wanted to stop its exports, “today, we can export oil anywhere we want, and with minimal discounts”.