South Korean President Lee Jae Myung takes questions during a news conference to mark 100 days in office at the Blue House in Seoul Thursday. Pool Photo by Kim Hong-ji/Reuters/EPA

SEOUL, Sept. 11 (UPI) -- South Korean President Lee Jae Myung said Thursday that last week's "perplexing" immigration raid at a Hyundai electric battery plant in Georgia, which led to the detention of more than 300 South Korean workers, could prevent firms from making future investments in the United States.

"Companies will have to worry about whether establishing a local factory in the United States will be subject to all sorts of disadvantages or difficulties," Lee said at a press conference in Seoul marking his 100th day in office.

"That could have a significant impact on future direct investment," he said.

Multiple agencies led by U.S. Immigration and Customs Enforcement arrested 475 people, most of whom are South Korean nationals, at a Hyundai-LG Energy Solutions battery plant near Savannah, Ga., last Thursday.