In response to the new US decision to impose a ban on the Iranian petrochemical sector, Mehdi Safari, Iran's Deputy Foreign Minister for Economic Diplomacy, pointed out that this sector had already been subject to sanctions.

"Our petrochemical industry and its products have long been under sanctions, but our sales have continued through various channels and shall continue to do so," Safari told Iranian state TV.

Earlier, the US Treasury Department said it was imposing sanctions on a network of Iranian petrochemical firms including alleged front companies in China and the United Arab Emirates for Iran's state-owned company and Triliance, a Hong Kong-based company already under US sanctions for its dealing with Tehran.

According to the Treasury, the sanctioned network "helps effectuate international transactions and evade sanctions, supporting the sale of Iranian petrochemical products to customers in the (People's Republic of China) and the rest of East Asia."

The US Treasury Department also targeted China-based broker Jeff Gao and Indian national Mohammad Shaheed Ruknooddin Bhore for allegedly managing business for Triliance.

"Absent a deal, we will continue to use our sanctions authorities to limit exports of petroleum, petroleum products and petrochemical products from Iran," said Brian Nelson, senior Treasury Department official.

The United States has sought to prevent any nation from buying Iranian oil since 2018 after then-president Donald Trump walked away from a negotiated agreement.

China has remained the top buyer of Iranian oil while India ended imports under US pressure.