SEOUL, Sept 9, 2025 (BSS/AFP) - South Korea plans to send a chartered plane as early as Wednesday to bring back hundreds of workers detained in a US immigration raid, the country's flag carrier Korean Air told AFP.

US immigration officials detained some 475 people, including hundreds of South Korean workers, during a massive raid Thursday at a Hyundai-LG battery plant being built in the southern state of Georgia.

Officials in the United States called it the largest such raid on a single site carried out so far under President Donald Trump's nationwide anti-immigration crackdown.

Seoul's foreign minister left for Washington on Monday for further talks, calling the mass detention of the country's nationals a "grave situation" and pledging to secure the workers' swift return "in good health."

The country's flag carrier Korean Air said it aims to send a chartered Boeing 747-8i as early as Wednesday to Atlanta.

"That is our goal for now," a Korean Air spokeswoman told AFP Tuesday.

Seoul has said that a deal to release and repatriate the detained workers had been "concluded" with the US, and that a chartered plane would fly them home once administrative procedures were complete.

In addition to being a key security ally on the Pacific Rim, South Korea is Asia's fourth-biggest economy and a key automaker and electronics producer with multiple plants in the United States.

Seoul has heeded Washington's repeated call for global investment in US businesses during tariff negotiations with countries around the world.

The site of the raid is a $4.3 billion joint venture between two South Korean firms -- Hyundai and LG Energy Solution -- to build a battery cell manufacturing facility in Georgia.

Experts say majority of detained South Korean workers were likely to have been on visas that do not allow for hands-on construction work.

Trump on Sunday warned foreign companies to obey US law following the raid, writing on social media: "Your Investments are welcome, and we encourage you to LEGALLY bring your very smart people."

LG Energy Solution has said 47 of its employees had been arrested -- 46 South Koreans and one Indonesian.

The company has also said about 250 of those arrested were believed to be employed by its contractor, and most of them were South Koreans.

Hyundai has said it understood none of those arrested are its employees.