SEOUL, South Korea: South Korea's LG Energy Solution was relying on U.S. visa workarounds long before President Donald Trump's recent immigration crackdown triggered the detention of hundreds of its workers, internal company documents show.

The August 2023 guidelines, reviewed by Reuters, advised LG staff and subcontractors to enter the United States using the Electronic System for Travel Authorization (ESTA) waiver program after repeated rejections of B-1 business visa applications.

This practice came under scrutiny earlier this month when U.S. authorities detained more than 300 Koreans — including 250 LG employees and contractors — in the Department of Homeland Security's largest-ever immigration raid at LG's battery venture with Hyundai Motor near Savannah, Georgia. Images of workers in shackles sparked outrage in South Korea, a close U.S. ally and major investor.

LG's guidelines included detailed tips for travelers, urging them to dress neatly, bring invitation letters from American partners, and avoid using the word "work" during customs interviews. "Using the word ‘work' to describe the purpose of your visit can cause suspicion and lead to U.S. entry denial," the guidelines said.

U.S. officials said the detained workers had overstayed their visas or engaged in activities beyond their authorization. Some of the workers' lawyers disputed that, saying they were doing legally permitted assignments. The employees have since been released and returned home to warm public receptions.

LG told Reuters it had advised staff to use ESTA because of high rejection rates for B-1 visas, noting that a B-1 denial would also block ESTA eligibility. The company said it updated its guidelines in March 2023, restricting ESTA use to assignments under one month and advising workers on longer projects to obtain B-1 or L-1 visas.

Still, about 44 percent of LG workers detained in Georgia had entered on ESTA, according to company data cited by South Korean lawmaker Han Jeong-ae.

Immigration lawyers say U.S. rules do allow short-term visitors to install or service equipment purchased abroad, train local staff, or stabilize production processes. "What began perhaps as a reasonable use of ESTA became an abuse," said U.S. immigration lawyer Robert Marton.

LG argued that its employees' activities fit within those definitions but also called for Washington to create a new visa category better suited to skilled technicians supporting U.S. factories.

South Korea's government has pressed for a resolution. According to Seoul, Deputy Secretary of State Christopher Landau expressed regret over the raid and agreed that both sides should speed up consultations to clarify visa rules and ensure smoother approvals.

The Trump administration has since signaled openness to revising policy to support South Korean investment in U.S. plants, even as it tightens overall enforcement.