WASHINGTON escalated its efforts to curb Iran’s oil trade and punish its enablers on Thursday, as it sanctioned a Chinese “teapot” refinery, and 21 entities and tankers it said were responsible for shipping millions of barrels of Iranian oil.

The move marked the fourth round of sanctions since US President Donald Trump announced the return of its “maximum pressure” campaign against Iran, and a ramp up of the administration’s efforts to deter third-party actors from touching Iranian barrels.

According to US advocacy group United Against Nuclear Iran, the refinery, Shandong Shouguang Luqing Petrochemical, imported at least 7.6m barrels of Iranian oil since 2023. The oil was labelled as Malaysian blend, the group said, which is common practice when Iranian barrels change hands in ship-to-ship transfers in the Riau Archipelago.

“For years, UANI has called for sanctions on teapot refineries like Luqing Petrochemical, which serve as key enablers of Iran’s sanctions evasion and illicit oil trade,” said UANI’s chief of staff Claire Jungman.

“Today’s designation is long overdue and underscores the vast, sophisticated network Iran relies on to fund terrorism, nuclear expansion and military aggression.”

China’s Shandong province is home to many semi-independent refineries dubbed “teapots” that are smaller and operate more opaquely than the state-owned companies. While Shandong Port Group recently announced it will stop accepting US-sanctioned tankers, Iranian oil is still arriving on board non-sanctioned tankers and sanctioned vessels continue to unload in terminals outside of SPG’s jurisdiction.

According to the US Office of Foreign Assets Control, Luqing imported oil from vessels linked to the Houthis and the Iranian Ministry of Defence of Armed Forces Logistics (MODAFL). The US also sanctioned Luqing’s chief executive, Wang Xueqing.

“Teapot refinery purchases of Iranian oil provide the primary economic lifeline for the Iranian regime, the world’s leading state sponsor of terror,” said Treasury secretary Scott Bessent.

“The United States is committed to cutting off the revenue streams that enable Tehran’s continued financing of terrorism and development of its nuclear programme.”

Separately but relatedly, the US State Department designated Huaying Huizhou Daya Bay Petrochemical Storage, a storage terminal in the port of Huizhou in Guangdong province.

The agency said Huaying Petrochemical “knowingly engaged in a significant transaction for the acquisition of crude oil from Iran in late January 2025”, when the US-sanctioned tanker Nichola (IMO: 9224271) offloaded about 1m barrels of Iranian crude oil at its terminal.

Shadow fleet tankers

Ofac also targeted eight “shadow fleet” vessels it accused of regularly engaging in “deceptive shipping practices, including automatic identification system manipulation”.

The vessels include five very large crude carriers, Natalina 7 (IMO: 9310147), Aurora Riley (IMO: 9181649), Catalina 7 (IMO: 9310159), Montrose (IMO: 9281695) and Titan (IMO: 9293741) and three aframaxes, Vernon (IMO: 9232876), Viola (IMO: 9254915) and Volans (IMO: 9422988). All eight appear on Lloyd’s List dark fleet* list.

The remaining 11 companies sanctioned on Thursday were shipmanagers and registered owners linked with the tankers.

* Lloyd’s List defines a tanker as part of the dark fleet if it is aged 15 years or over, anonymously owned and/or has a corporate structure designed to obfuscate beneficial ownership discovery, solely deployed in sanctioned oil trades, and engaged in one or more of the deceptive shipping practices outlined in US State Department guidance issued in May 2020. The figures exclude tankers tracked to government-controlled shipping entities such as Russia’s Sovcomflot, or Iran’s National Iranian Tanker Co, and those already sanctioned.