ISTANBUL 

South Korea on Friday expressed "concern and regret" over a US Immigration and Customs Enforcement (ICE) raid on the Hyundai-LG electric vehicle battery plant in the state of Georgia that detained its nationals, Yonhap news reported.

More than 300 South Koreans, among a total of 450, were taken into custody from the site on Thursday.

"The economic activities of our companies investing in the US and the rights and interests of our nationals must not be unfairly violated," said South Korean Foreign Ministry spokesman Lee Jae-woong.

"We conveyed our concern and regret through the US Embassy in Seoul today."

According to US authorities, the raid was part of an investigation into undocumented individuals, and the detainees face possible charges of illegal stay.

An ICE spokesperson said the raid was conducted in connection with an investigation into "unlawful employment practices and other serious federal crimes," according to NBC News.

Seoul did not receive any prior notice from Washington regarding the raid, a ministry official said on condition of anonymity.

The government has dispatched its embassy and consular officials in Washington and Atlanta to the site, instructing local diplomatic missions to establish an on-site task force to address the matter, the ministry said.

The detained South Koreans arrived in the US under a B1 visa, for business purposes, or with the Electronic System for Travel Authorization (ESTA) visa waiver program for short-term stays.

South Korea is a major automotive and electronics manufacturer, with companies operating multiple plants in the US.

In July, Seoul secured a 15% tariff rate with the US and pledged $350 billion in investments.

Under President Donald Trump, the ICE agency has cracked down on migrants.