US immigration officials raided a Hyundai Motor car battery factory on Thursday, local time, and later released a video and photos of workers shackled at the wrists, waist and ankles getting on a bus after the raid.
The crackdown could risk damaging ties between Washington and Seoul, a key Asian ally and US investor, when the two are trying to narrow their differences and finalise a trade deal after a summit between President Donald Trump and South Korean President Lee Jae Myung.
First Vice Foreign Minister Park Yoon-joo told US Under Secretary of State for Political Affairs Allison Hooker in a telephone call it was regrettable the incident "occurred at a critical time, when the momentum of trust and cooperation between the two leaders, forged through their first summit, must be maintained", the foreign ministry said in a statement.
Park also asked Hooker to ensure a fair and swift resolution to the matter.
"The economic activities of our companies that have invested in the US and the rights and interests of our citizens should not be unfairly infringed upon during the course of US law enforcement," he said.
The arrest of some 475 workers at the plant near Savannah, Georgia, included more than 300 Koreans and was the largest single-site enforcement operation in the US Department of Homeland Security's history.
The video and photos of the raid, which involved a helicopter and armoured vehicles, showed hundreds of workers standing in front of a building, some wearing yellow vests with the names Hyundai or LG CNS. Two workers hid in a pond before they were arrested.
US lawmakers from Georgia and the Congressional Asian Pacific American Caucus said they were "deeply alarmed" by the massive raid.
"Instead of targeting violent criminals, the Trump administration is going after immigrants at work and in communities of colour to meet its mass deportation quotas," they said in a statement.
"These senseless actions rip apart families, hurt the economy, and undermine the trust of our global partners."
Korean President Lee Jae Myung ordered a swift, all-out response to the arrests, Foreign Minister Cho Hyun said at an emergency meeting on Saturday. Cho said he may go to Washington to meet with officials if needed.
LG Energy Solution, which is working with Hyundai to build the factory, said it had asked employees to return from US business trips while suspending travel to the United States except for customer meetings.
The company said it had sent a human resources executive to Georgia to "ensure the swift and safe release of those detained".
Hyundai Motor said it would investigate its suppliers and their subcontractors to ensure they meet regulations.
Trump, when asked about the raid, said on Friday: "I would say that they were illegal aliens and ICE was just doing its job."
