US Customs and Border Protection has issued a Withhold Release Order against copper and copper products manufactured by Serbia Zijin Copper, directing all US ports of entry to detain shipments from the Chinese-controlled Serbian copper producer following an investigation that found evidence of six International Labour Organization indicators of forced labour.
CBP said its investigation drew on worker statements, photographs, focus group field notes, text message screenshots, NGO reports, news media and academic research. The evidence collectively demonstrated that workers at Serbia Zijin Copper are subject to abuse of vulnerability, withholding of wages, intimidation and threats, restriction of movement, retention of identity documents and excessive overtime.
Importers of detained shipments may either destroy or export their goods, or seek to demonstrate to CBP that the merchandise was not produced using forced labour. Serbia Zijin Copper had not responded to a request for comment at time of publication.
“US manufacturers face unfair competition when foreign companies cut costs by using forced labour. By enforcing our laws against forced labour, CBP safeguards human rights as well as our nation’s economic security,” said Susan S. Thomas, CBP Office of Trade executive assistant commissioner.
Serbia Zijin Copper was created in 2018 when China’s Zijin Mining injected $350 million into Serbian copper mining and smelting company RTB Bor, acquiring a 63% stake. In 2025, the company produced 123,286 tonnes of mine copper and 43,852 tonnes of refined copper. Zijin is also present in Serbia through wholly-owned Serbia Zijin Mining, which operates the Čukaru Peki copper-gold mine. Combined, the two Zijin operations in Serbia produced 296,000 tonnes of mine copper in 2025, making them Europe’s second-largest mined copper producer. A 2025 UN Special Rapporteur report noted that most of this copper is exported to China.
Tuesday’s order is the fourth forced labour Withhold Release Order issued by CBP in fiscal year 2026, following a December 2025 order against tyres produced by Chinese company Linglong’s Serbian factory on the same grounds.
