A massive immigration raid on a battery plant in Georgia earlier this month continues to reverberate across the region with workers staying home and delays mounting.

Ken Shim, president of Woowon Technology Inc., says he’s had to provide paid time off to ease the stress of South Korean engineers installing equipment at a cell plant being built by Hyundai Motor Co. and Korea’s SK On Co. near Cartersville, Georgia.

Shim, an American citizen who has lived in the U.S. for more than a decade, stresses that his employees are all working legally — they have visas that allow for limited business activity such as training local hires and setting up equipment. But Hyundai and LG Energy Solution Ltd. also thought workers and subcontractors at their plant outside the city of Savannah on similar visas were complying with the law. Yet on Sept. 4, they were shackled and detained by Immigration and Customs Enforcement officers.

“They stopped going to work. Everybody right now is staying in their hotels or houses,” Shim said in an interview. “I told my people — don’t worry about it, take it as a one-week vacation. Go shopping, you guys work hard.”

SK has advised some visa holders to avoid coming to U.S. work sites until there is more clarity around their legal status, Shim said. His workers in Georgia are hunkered down, citing rumors of immigration agents questioning people at Walmart and H Mart, a grocery chain that specializes in Asian foods. He understands their worries, and advised everyone to carry their visa and passport documents with them.

SK didn’t respond to a request for comment. The White House and Department of Homeland Security didn’t respond to requests for comment.

Korean battery manufacturers have invested billions in the U.S. over the past few years as the electric-vehicle industry has ramped up production in anticipation of a boom in demand. That business plan is being tested now as EV sales have lost steam and after Republicans eliminated consumer tax credits that helped stimulate EV demand.

The immigration uncertainty has added to stress on their businesses. Worker unease at the Hyundai-SK plant in Cartersville is emblematic of what’s happening at other factory floors across the country. Hyundai has acknowledged the raid set back construction at its site near Savannah by at least several months due to workers’ fears of being detained.

It’s no small problem for the industry. South Korean firms are building or have plans to build some 22 plants in the U.S., projects the companies say hinge on moving trained engineers quickly across international borders — a practice being undermined by heightened immigration scrutiny. There are at least four additional major EV battery plants actively under construction in the U.S. that are seen as vulnerable to similar raids because they still require the services of skilled technicians on temporary visas.

The saga began when federal authorities swooped in at the Hyundai-LG plant outside Savannah on Sept. 4, detaining about 475 workers — over 300 of them South Koreans — amid allegations at least some were working in the U.S. illegally. After diplomatic pressure, a group of the South Koreans who had been detained were flown back home several days later.

Following the raid, President Donald Trump said foreign companies investing in the U.S. need to respect immigration laws — one of his signature priorities — but he also acknowledged that some specialized foreign workers are needed to train Americans in jobs where they’re developing complex products and machines.

The situation has pinned Trump between dueling priorities — an immigration crackdown and a desire for more foreign investment, which brings with it a demand for work visas. It also risks fueling tensions between the U.S. and South Korea; the two countries have reached a deal to curb tariffs and set up a Korean-financed investment fund, but it hasn’t been signed.

LG, which is also building a battery plant in Ohio as part of a joint venture with Honda Motor Co., said construction at its other U.S. plants is going forward, albeit without the help of foreign battery engineers whose visa status is in limbo.

“This is mostly manageable and something that should not interrupt our operations,” Bob Lee, president of North America for LG, said at a conference in Detroit on Tuesday. “We have to try to find a plan that works regardless of various different scenarios, so that’s what were doing.”

Shim said that battery factories that are already up and running, like the SK plant in Commerce, Georgia, have been less affected by visa confusion because most of the local workforce, largely citizens and green card holders, have already been trained on how to monitor the complex battery manufacturing machines. But new plants that haven’t started production are facing delays because locals haven’t been fully trained yet.

“We couldn’t finish all the training, and still the machine setup and teaching to optimize for the production was not completed yet,” he said. “They could do some, but not really what they’re supposed to do at this stage.”

Woowon Technology, whose parent company is based in Pyeongtaek, South Korea, produces, installs and services equipment for assembling battery cells. It also invested in a 10,000 square-foot workshop in Kentucky, near a Ford Motor Co.-SK battery joint venture, that maintains blades to cut battery electrodes.

In a statement, the company said it’s worried about workers being detained even though it follows immigration law. “If such uncertainty continues, it could negatively affect Korean companies’ willingness to invest in and cooperate with U.S. manufacturing,” the statement said.

Shim said when he first heard about the raid at the Hyundai-LG plant, it sounded like the result of a misunderstanding and he assumed it would quickly be cleared up.

“The first week, we thought, ‘This is happening, but everything will be OK, this is America, we are all legal,’” Shim said. “But maybe now, maybe this is not OK.”

“After that instant, the kind of the feeling we are having here in the U.S. is completely different,” he said.

(With assistance from Josh Wingrove and Myles Miller.)

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