"We're going to be doing more enforcement in the workplace," Homan said. White House border affairs director Tom Homan recently said that after U.S. Immigration and Customs Enforcement (ICE) and other law enforcement agencies raided a Hyundai Motor-LG New Energy joint venture plant in Georgia, resulting in the arrest of hundreds of Korean citizens, the Trump administration plans to list more companies as immigration enforcement targets.

"We will conduct more enforcement in the workplace," Homan said. "People who hire illegal immigrants do not have the best of intentions. They hire illegal immigrants because they can make them work harder and pay less, making it less competitive to hire U.S. citizen employees."

Trump: Foreign companies should hire and train more Americans

Last week, U.S. Immigration and Customs Enforcement (ICE) and other law enforcement agencies raided the Hyundai Motor-LG New Energy joint venture battery plant in Georgia and arrested 475 people, most of whom were Korean citizens. An immigration official told a news conference that some of those arrested at the plant had crossed the border illegally and overstayed their visas. Another immigration official said many of those arrested were holding tourist and business visitor visas that did not include work authorization.

In the early hours of Monday morning, Trump said on social networking sites that he called on "all foreign companies investing in the United States to respect U.S. immigration laws" following immigration enforcement actions targeting a Hyundai vehicle battery plant in Georgia.

"We welcome your investment and encourage you to legally bring in your talented people and technical talent to build world-class products. We will quickly and legally provide you with a way to achieve this goal. In return, we ask you to hire and train American workers." Trump later told the media, "I think they (South Korean workers) are illegal immigrants, and the Immigration Service is just doing its job."

Steven Schrank, who is leading the investigation into the Georgia immigration enforcement operation, said at a press conference that the investigation has been ongoing for several months.

"The United States is proud to be home to significant investments and looks forward to continuing to build on these historic investments and partnerships that President Trump has brokered," White House spokesperson Abigail Jackson wrote in a statement on Monday. However, "any foreign workers brought in for a specific project must enter the United States legally and hold the appropriate work authorization."

Lawyer: It takes three to five years to train Americans

Charles Kuck, the immigration lawyer for several of the workers detained at the plant, said on Monday that many of the South Koreans captured in the immigration raid were engineers and equipment installers who came to the United States to take highly specialized jobs putting a battery factory into operation.

Cook said many of them hold jobs that qualify for the B-1 business visitor visa program. He said they originally planned to stay in the United States for a few weeks, "no more than 75 days."

Video released by U.S. Immigration and Customs Enforcement showed some people being handcuffed at their hands, ankles and waists during the arrests. South Korea's Foreign Minister flew to the United States on Monday to ensure that these South Korean citizens returned to South Korea on chartered flights.

Trump said the United States should consult with other countries "to allow experts from these countries to train American citizens in professional jobs such as battery and computer manufacturing."

Cook said no U.S. company makes the machines used at the Georgia battery plant, which must be brought in from abroad to be installed or repaired on-site. But in the United States, it takes about three to five years to train someone to do the job. "This is nothing new," Cook said. "We've always done it this way. When we ship goods overseas, we send our employees there to process them."

Neither the U.S. nor South Korean governments have disclosed details of all worker visas.

Rosemary Coates, executive director of the Manufacturing Reshoring Institute, a nonprofit organization that encourages the development of American manufacturing, said foreign companies often send overseas workers to set up factories in the United States to save time and money and then train American workers. "We saw Japanese automakers do this in the 1980s when they set up factories in the United States, and we saw German automakers do the same in the 1990s when they set up factories in the United States," she said.

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