Kang Hoon-sik, chief of staff for President Lee Jae Myung, said South Korea and the US had finalised negotiations on the workers' release.
He said South Korea plans to send a charter plane to bring the workers home as soon as remaining administrative steps are completed.
Foreign Minister Cho Hyun is to leave for the US on Monday for talks related to the workers' releases, South Korean media reported.
US immigration authorities said on Friday they detained 475 people, most of them South Korean nationals, when hundreds of federal agents raided Hyundai's sprawling manufacturing site in Georgia where the Korean automaker makes electric vehicles.
Cho said more than 300 South Koreans were among the detained. The operation was the latest in a long line of workplace raids conducted as part of the Trump administration's mass deportation agenda.
But it was especially distinct because of its large size and because the targeted site has been touted as Georgia's largest economic development project.
The raid stunned many in South Korea because the country is a key US ally. It agreed in July to purchase $US100 billion ($A153 billion) in US energy and make a $US350 billion ($A534 billion) investment in America in return for the US lowering tariff rates.
About two weeks ago, US President Donald Trump and Lee held their first meeting in Washington.
Trump said perhaps the US could work out an arrangement with South Korean workers who would train American citizens to do work such as battery and computer manufacturing.
"If you don't have people in this country right now that know about batteries, maybe we should help them along and let some people come in and train our people," Trump said on Sunday night.
He added "the way you train people is bring people in that know what they're doing, let them stay for a little while and help."
Lee said the rights of South Korean nationals and economic activities of South Korean companies must not be unfairly infringed upon during US law enforcement procedures.
South Korea's Foreign Ministry separately issued a statement to express "concern and regret" over the case and sent diplomats to the site.
Steven Schrank, the lead Georgia agent of Homeland Security Investigations, told a Friday news conference some of the detained workers had illegally crossed the US border, while others had entered the country legally but had expired visas or had entered on a visa waiver that prohibited them from working.
Kang, the South Korean presidential chief of staff, said South Korea will push to review and improve visa systems for those travelling to the US on business trips for investment projects.
