South Korea's government has launched an investigation into potential human rights violations during a large-scale U.S. immigration raid at a Hyundai-operated electric vehicle battery plant in Georgia, where over 300 Korean nationals were detained, heightening diplomatic strains between the allies even as Seoul pledges support for its citizens' return.

The probe follows the September 4, 2025, operation by U.S. Immigration and Customs Enforcement (ICE), which apprehended 475 workers – mostly South Koreans – at the Hyundai-LG Energy Solution facility in Ellabell, near Savannah. ICE described the action as targeting unlawful employment and federal crimes, with officials stating the workers had overstayed visas or lacked work authorization.

Witnesses recounted scenes of panic, with federal agents arriving in armored vehicles, some using tear gas and handcuffing detainees at the waist and ankles before transporting them to a detention center in Folkston, Georgia.

A presidential spokesperson announced Monday that Seoul expressed "strong regret" to Washington and formally requested safeguards for Korean citizens' rights during enforcement actions. Diplomats were dispatched to the site from Washington and Atlanta, and the foreign ministry has coordinated with the companies involved to examine the raid's conduct. "The economic activities of our investment companies and the rights and interests of our nationals must not be unjustly violated," spokesperson Lee Jaewoong stated at a news conference.

Over 300 detainees, many mechanics and subcontractors sent to install production lines, returned home Friday via chartered flights arranged by South Korea's government. LG Energy Solution suspended most U.S. business trips and sent its chief human resources officer to Georgia, while Hyundai confirmed the plant's opening would delay by at least two months.

President Lee Jae-myung called the situation "bewildering," noting it's standard for Korean firms to dispatch experts for overseas projects, and warned it could deter future investments amid a $350 billion U.S.-South Korea trade deal aimed at avoiding tariffs.

Trade unions in South Korea demanded an official U.S. apology, and civil rights groups like Asian Americans Advancing Justice criticized the raid's scale and treatment, citing a 2022 Department of Homeland Security report on deficiencies at the Folkston facility, including medical neglect.

U.S. Senator Raphael Warnock (D-Georgia) questioned the raid's impact on the economy and due process, while President Donald Trump defended it on Truth Social, saying foreign workers are "welcome" if they follow immigration laws and that the U.S. aims to learn from experts in fields like shipbuilding and chips.