CBP Issues Withhold Release Order Against Serbian Copper Producer Over Forced Labor Concerns

On June 16, 2026, U.S. Customs and Border Protection (CBP) announced a new Withhold Release Order (WRO) against copper and copper products manufactured by Serbia Zijin Copper DOO, citing reasonable evidence that forced labor was used in the production of the company’s products.

Effective immediately, CBP officers at all U.S. ports of entry are authorized to detain covered copper products imported into the United States. The action marks the fourth WRO issued by CBP during fiscal year 2026 and serves as another example of the agency’s continued focus on enforcing U.S. prohibitions against goods produced with forced labor.

Understanding the WRO Authority

The WRO was issued pursuant to Section 307 of the Tariff Act of 1930 (19 U.S.C. § 1307), which prohibits the importation of merchandise mined, produced, or manufactured wholly or in part by forced labor.

Under this authority, CBP may issue a WRO when it has information that reasonably indicates forced labor was involved in the production of imported goods. Once a WRO is issued, covered products are detained at U.S. ports of entry unless the importer can demonstrate that the merchandise was not produced using forced labor.

Unlike enforcement actions under the Uyghur Forced Labor Prevention Act (UFLPA), which rely on statutory presumptions tied to specific regions and entities, WROs can be issued against producers located anywhere in the world when CBP identifies sufficient evidence of forced labor.

Evidence Supporting the Action

According to CBP, the WRO follows an investigation and evidence review that identified multiple indicators of forced labor within Serbia Zijin’s operations.

The agency’s review reportedly included:

• Worker statements;
• Photographic evidence;
• Focus group research findings;
• Screenshots of text message communications;
• Reports from non-governmental organizations;
• News media reporting; and
• Academic research materials.

Based on its findings, CBP concluded that the company exhibited all six indicators of forced labor identified during its investigation.

Indicators of Forced Labor Identified by CBP

CBP stated that the evidence demonstrated the presence of six internationally recognized indicators of forced labor, including:

• Abuse of worker vulnerability;
• Withholding of wages;
• Intimidation and threats;
• Restriction of movement;
• Retention of identity documents; and
• Excessive overtime.

These indicators are consistent with forced labor risk factors recognized by the International Labour Organization (ILO) and frequently relied upon by CBP when evaluating forced labor allegations.

According to the agency, the evidence suggested that workers were compelled to perform labor involuntarily under the threat of penalty, creating reasonable suspicion that the goods were produced using forced labor.

Impact on Importers

The WRO has immediate implications for importers of copper and copper products sourced from Serbia Zijin.

CBP indicated that import trade data confirms that products manufactured by the company have entered—or may enter—the U.S. market. As a result, importers should carefully review their supply chains to determine whether any products, components, or raw materials originate from the affected producer.

When goods are detained pursuant to a WRO, importers generally have several options:

• Export the merchandise from the United States;
• Destroy the merchandise under CBP supervision; or
• Submit evidence demonstrating that the goods were not produced using forced labor.

Successfully challenging a detention often requires detailed supply chain documentation, production records, labor compliance evidence, and other supporting materials capable of rebutting CBP’s concerns.

A Reminder That Forced Labor Enforcement Is Global

The Serbia Zijin action highlights an important reality for importers: forced labor enforcement is not limited to a particular country, region, or industry.

While much recent attention has focused on UFLPA enforcement involving products connected to China’s Xinjiang region, CBP continues to utilize traditional WRO authority to investigate and restrict imports from suppliers around the world. Industries involving mining, metals, agriculture, seafood, apparel, and other labor-intensive sectors remain subject to heightened scrutiny.

For importers, this development reinforces the importance of maintaining comprehensive supplier due diligence programs, supply chain visibility, and documentation capable of demonstrating compliance with U.S. forced labor laws.

Looking Ahead

As CBP continues to expand its forced labor enforcement efforts, importers should expect increased scrutiny of upstream suppliers and raw material sources, particularly in industries associated with elevated labor rights risks. The Serbia Zijin WRO serves as another reminder that companies must evaluate forced labor risks throughout their global supply chains—not only in traditionally high-profile jurisdictions.

Businesses importing goods into the United States should regularly assess supplier compliance, traceability systems, and forced labor due diligence procedures to reduce enforcement risk and prepare for potential CBP inquiries or detentions.

Liang + Mooney PLLC assists importers with customs compliance, forced labor due diligence, supply chain risk assessments, WRO matters, UFLPA compliance, and responses to CBP enforcement actions. If your company has questions regarding forced labor compliance obligations or is facing a detention, exclusion, or seizure by CBP, contact our team to schedule a consultation.

Disclaimer: This article is provided for informational purposes only and does not constitute legal advice; readers should consult qualified counsel regarding their specific circumstances.