DETROIT (Reuters) -A battery plant co-owned by Hyundai Motor is facing a minimum delay of two to three months following an immigration raid last week, Hyundai's CEO Jose Munoz said Thursday. 

The Georgia plant, which is operated through a joint-venture between Hyundai and South Korea's LG Energy Solution, was at the center of the largest single-site enforcement operation in the U.S. Department of Homeland Security's history. 

Munoz, in his first public comments since the raid, said he was surprised when he heard the news and immediately inquired if Hyundai workers were involved. He said the company discovered that the workers at the center of the raid were mainly employed by suppliers of LG. 

It is typical for an automotive battery plant to employ these workers as it's getting off the ground, Munoz said. 

"For the construction phase of the plants, you need to get specialized people. There are a lot of skills and equipment that you cannot find in the United States," Munoz said, on the sidelines of an automotive event in Detroit.