The United States' sanctions on Chinese companies contravene international law and the basic norms of global relations, while Beijing's blocking measure aims to safeguard the legitimate rights and interests of domestic firms and individuals, the Ministry of Commerce and analysts said.

The ministry issued a ban on Saturday prohibiting any recognition, enforcement or compliance with US sanctions imposed on five Chinese companies, including Hengli Petrochemical (Dalian) Refining Co and Shandong Shouguang Luqing Petrochemical Co, on the grounds of their alleged involvement in Iranian petroleum transactions.

Since 2025, the US government has imposed sanctions on these Chinese firms under executive orders, placing them on the Specially Designated Nationals List, freezing their assets and prohibiting transactions with them.

In response, a spokesperson for the ministry said that China has consistently opposed unilateral sanctions lacking United Nations authorization and a basis in international law, adding that the prohibition order represents a concrete step under China's Rules on Counteracting Unjustified Extra-territorial Application of Foreign Legislation and Other Measures, which was approved by the State Council in 2021.

The issuance of the ban does not affect China's fulfillment of its international obligations or its protection of the legitimate rights and interests of foreign-invested enterprises under Chinese law, the ministry official stressed.

Hengli Petrochemical, the parent company of Hengli Petrochemical (Dalian) Refining Co, condemned the US sanctions last week, dismissing US allegations of ties to Iran as "groundless" and lacking both factual and legal grounds.

"The company has strictly complied with laws and regulations since its inception. We have never engaged in any trade with Iran, and our suppliers guarantee that the origin of our crude oil does not fall under US sanctions," Hengli Petrochemical said in a public filing.

Analysts said that the US has long leveraged the dominance of its currency and financial system to extend the reach of its sanctions. Secondary sanctions — targeting entities dealing with blacklisted parties — have become a key policy tool to reshape global supply chains and influence cross-border commercial activities.

Mei Xinyu, a researcher at the Chinese Academy of International Trade and Economic Cooperation in Beijing, said that China maintains a neutral stance toward external conflicts, but will not tolerate infringements on the legitimate rights of its citizens and businesses.

"Safeguarding those interests is a necessary response to external pressures," said Mei. "At the same time, such measures do not alter China's broader commitment to openness, international cooperation and a stable, predictable environment for foreign investment."

Ding Rijia, a professor of industrial economy at China University of Mining and Technology-Beijing, said China's latest step highlights the country's growing use of legal instruments to counter the extraterritorial application of foreign sanctions.

"It sends a signal to both domestic and multinational companies that China is capable of providing a more predictable legal environment for cross-border trade," said Ding.

He added that the policy measure will help reduce compliance uncertainty for firms operating in multiple jurisdictions, while reinforcing the resilience of global supply chains in the face of rising unilateralism.

Zhang Xin, head of customs affairs at Oriental Energy (Ningbo) New Material Co, a Ningbo, Zhejiang province-based petrochemicals producer, said a predictable policy environment is fundamental to the sound development of China-US economic and trade relations, adding that the company will maintain US imports and optimize supply chains to ensure stable raw material supply.

The company imported 258,000 metric tons of liquefied propane from the US, valued at $150 million, in the first four months of this year, according to data from Ningbo Customs.