None of the people arrested at the site last week were directly employed by Hyundai, according to the company.
LG Energy Solution, which operates the battery plant in Georgia with Hyundai, said that many of its employees who were arrested had various types of visas or were under a visa waiver programme.
At a press conference on Thursday, South Korea’s president said if such arrangements were no longer allowed, it would make building factories in the US “more difficult… making companies question whether it’s worth doing at all”.
The situation has raised questions about the viability of the trade deal that the US and South Korea had agreed earlier this year, in which President Donald Trump had agreed to drop some of his steepest tariff threats, in exchange for promises of billions of dollars of investment.
Hyundai alone had pledged $26bn (£19.2bn), including a new steel factory in Louisiana that had been celebrated by Trump, who has made boosting foreign investment in the US to revive manufacturing a top priority.
The site of the raid is part of a bigger complex in Georgia that is eventually supposed to create 8,500 jobs and had been hailed as the largest economic development project in the state’s history.