China has ordered its domestic companies to ignore U.S. sanctions imposed on five Iranian oil refiners, including Hengli Petrochemical's Dalian unit, which were sanctioned last month. The Chinese commerce ministry invoked a 2021 blocking law to protect its firms from what it deems unjustified foreign measures. The ministry stated that these sanctions unlawfully restrict normal trade with third countries and violate international norms. This directive reflects China's consistent opposition to unilateral sanctions that lack United Nations backing. Analysts suggest that while this move may not impact the upcoming summit between U.S. President Donald Trump and Chinese President Xi Jinping, any escalation in U.S. sanctions could provoke stronger countermeasures from Beijing. China is the largest buyer of Iranian crude oil, with much of it processed through private refiners, which account for about one-third of China's refining capacity, emphasizing the nation's focus on energy security.