South Korean workers that experts have said are necessary for the speedy construction of large-scale manufacturing projects in the U.S. are questioning whether or not to return to the U.S. after a Sept. 4 Immigration and Customs Enforcement raid at the site of an under-development Hyundai-LG battery plant in Ellabell, Ga., earlier this month detained 475 workers—317 South Koreans—in reportedly poor conditions.[time-brightcove not-tgx=”true”]One detainee secretly kept a diary of the dayslong detention on a folded up sheet of paper detailing their alleged mistreatment in the ICE facility, which was obtained by South Korean news agency Yonhap. Meanwhile, immigration lawyer Charles Kuck, who represents seven of the detained South Koreans, said his clients had entered and were working in the U.S. legally, and a leaked ICE document showed that at least one detainee had a valid visa, according to the Guardian.President Donald Trump reportedly sought for the workers to stay in the U.S. and train American workers, a request that delayed their return to South Korea. But 330 detainees—316 Koreans and 14 other foreign nationals—opted to return to Seoul, where they were greeted with cheers on Friday. Just one South Korean worker chose to stay in the U.S.“Nobody is going to stay and work when it’s like this,” Jang Young-seol, an engineer for an LGES subcontractor, told Reuters.'Nobody is going to stay and work when it's like this,' said an LG Energy Solutions subcontractor who was among the 300 South Koreans who returned to their country after being detained in a US immigration raid https://t.co/3ee9ngrW6z pic.twitter.com/64AoChHpYa— Reuters (@Reuters) September 13, 2025The detentions of the workers had caused an uproar in South Korea—a security ally and longtime friend of the U.S.—with lawmakers and diplomats criticizing the U.S.’s visa system. It has also led some South Korean firms to question their investments in the U.S. The raid came just weeks after South Korea had pledged to directly invest $350 billion in the U.S. as part of a trade deal. Experts have told TIME that Trump’s aggressive immigration crackdown is butting heads with his push to attract foreign investment and bring manufacturing back to the U.S. The Hyundai-LG battery plant, which is expected to create thousands of American jobs, faces a startup delay of at least two to three months as a result of the raid.Poor conditions in ICE detention facilityThe diary obtained by Yonhap described the detained workers being kept in cramped and unsanitary conditions while being given little explanation for their detentions.At around 10 a.m. on Sept. 4, ICE agents raided the plant, searching the workers who had been in hard hats and safety shoes and rounding them up, tying their wrists with cable ties, according to the diary. The diary writer was not allowed to get his ID or passport.According to the diary, the workers were told to fill in paperwork for a foreign arrest warrant, without any explanation of the documents or the detainees’ legal rights. Some of the workers reportedly had limited knowledge of English.“We handed in the papers thinking that we would be released after filling them out,” the worker reportedly wrote in the log. But after filling out the documents, the ICE agents confiscated the belongings of the workers and boarded the workers into police vans, the diary said, transporting some with chains around their waists, ankles, and wrists. The diary writer waited more than nine hours before being boarded onto a van with his wrists bound by zip ties.The workers were initially kept in five temporary 72-person cells, according to the diary, that were so cold that the detainees wrapped themselves in towels. The facility reportedly did not have a clock, and the mattresses were moldy. Eventually, some detainees were moved to assigned cells.South Korean daily newspaper Hankyoreh reported that the detainees’ waists and hands were tied, which forced them to bend down and lick in order to drink water. Toilets were reportedly not covered, so the workers had to use a small sheet to cover themselves. Workers told the newspaper there was just a fist-sized hole for sunlight to come through.Cho Young-hee, a 44-year-old South Korean engineer who was in the U.S. on a B-1 visa, told the Wall Street Journal that he was assigned to a two-person room with a toilet and given a prison uniform.It did not seem as though ICE agents knew why the workers had been detained, Cho said. “It felt like our basic human rights weren’t being guaranteed,” he said.“Their initial attitude was very aggressive,” but “as time went on, it seemed like they realized we hadn’t committed any major illegal acts,” Cho said. Even the agents “gradually seemed to think, ‘Something’s not right here,’” he added.Cho told the Journal that he was not sure what his legal status would be when returning to the U.S., although the Trump Administration has all but guaranteed that the workers can re-enter without issue. Cho’s wife, however, said, “I don’t want him to go back there.”Workers detained despite holding valid visasThe diary writer had reportedly entered the U.S. on a legal short-term business visa. Workers were given “voluntary departure” forms describing them as being in the U.S. illegally and told to sign, according to the detention log.One 40-year-old employee of an LGES subcontractor told Hankyoreh, “I didn’t even know I was under arrest. I thought it was a procedure to confirm my identity, but they asked me to sign some document.” Another 48-year-old employee said, “They saw the word ‘arrest’ on the document and whispered that they shouldn’t do it, but the agents were holding guns, so they ended up signing anyway.”After three days of being confined, according to the worker’s diary, they were brought to an interview with ICE agents who took their fingerprints and examined their documents. The agents reportedly made jokes about “Rocket Man”—Trump’s nickname for North Korean leader Kim Jong Un—after confirming that the worker was from South Korea.“I was angry that they seemed to be making fun of me, but kept my temper because I was worried about what could happen to my documents,” the worker wrote. The worker informed the agents that they had entered the U.S. legally and asked why they were arrested, to which the agent reportedly said they didn’t know but that their higher-ups thought it was illegal.On Sept. 7, the South Korean consulate and foreign ministry officials met with the detainees, reportedly telling them, “The most important thing is for everyone to go home first. You must sign whatever you are asked to sign here.”The consulate officials reportedly told the workers that if there was a dispute, the workers could be detained for months or even years.Trump Administration seeks to mend rift“We’re in an age of new normal in dealing with the United States,” Presidential Chief of Staff Kang Hoon-sik told reporters at the airport. “The standard changes every time and constantly there has to be deal-making, not only on tariffs, but it’ll also be the case with security issues.”Deputy Secretary of State Christopher Landau expressed regret over the detentions in a meeting with South Korean Vice Foreign Minister Park Yoon-joo.Trump too has tried to mollify the situation, after initially telling reporters that “ICE was doing right because they were here illegally” and urging foreign companies “to LEGALLY bring your very smart people.”Trump posted on Sunday, “When Foreign Companies who are building extremely complex products, machines, and various other ‘things,’ come into the United States with massive Investments, I want them to bring their people of expertise for a period of time to teach and train our people how to make these very unique and complex products, as they phase out of our Country, and back into their land. If we didn’t do this, all of that massive Investment will never come in the first place — Chips, Semiconductors, Computers, Ships, Trains, and so many other products that we have to learn from others how to make, or, in many cases, relearn, because we used to be great at it, but not anymore.”South Korean officials and businesses have complained that obtaining U.S. visas costs a significant amount of both time and money, an issue that has only worsened as the Trump Administration cracks down on legal immigration pathways. The Trump Administration is reportedly in talks with South Korean officials to create a new visa category.“I don’t want to frighten off or disincentivize Investment into America by outside Countries or Companies,” Trump added. “We welcome them, we welcome their employees, and we are willing to proudly say we will learn from them, and do even better than them at their own ‘game,’ sometime into the not too distant future!”