More than 300 South Korean workers were released from U.S. Immigration and Customs Enforcement (ICE) custody Thursday and are expected to arrive back in their home country on Friday, according to South Korea’s foreign ministry.

The Trump administration released 330 detainees — including 316 Koreans, 10 Chinese nationals, three Japanese nationals and one Indonesian — who were transported by bus to Atlanta’s Hartsfield-Jackson airport, where they are expected to board a plane chartered by South Korea’s government.

The release comes nearly a week after the Department of Homeland Security (DHS) carried out what it said was the “largest single site enforcement operation” in the agency’s two-decade history.

DHS detained 475 people, mostly Korean nationals, during the ICE operation. The immigration enforcement operation was a result of a monthlong investigation into illegal hiring at the site, where Hyundai is teaming up with LG Energy Solution to manufacture batteries to power electric vehicles. The site has been lauded as the state’s largest economic development project.

South Korean President Lee Jae Myung, who initially called the raid an “unjust infringement,” said Sunday that its government reached a deal with the U.S. to secure the release of its citizens and bring them home on a chartered plane. At the time, a spokesperson for Lee’s office said “administration procedures” still needed to be finalized in the deal.

The South Korean leader also called for the Trump administration to make improvements to the. visa system during a press conference Thursday, marking his 100 days in office. He said unless the U.S. makes it easier for foreign companies to send skilled workers, those in his nation may be hesitant to make those investments in the future.

“It’s not like these are long-term workers,” Lee said. “When you build a factory or install equipment at a factory, you need technicians, but the United States doesn’t have that workforce and yet they won’t issue visas to let our people stay and do the work.”

“If that’s not possible, then establishing a local factory in the United States will either come with severe disadvantages or become very difficult for our companies,” he continued. “They will wonder whether they should even do it.”

He also noted that there are “cultural differences” in the way the two countries approach visa matters.

“In South Korea, we see Americans coming on tourist visas to teach English at private cram schools — they do it all the time, and we don’t think much of it, it’s just something you accept,” Lee said, adding, “But the United States clearly doesn’t see things that way.”

The leader continued, “On top of that, U.S. immigration authorities pledge to strictly forbid illegal immigration and employment and carry out deportations in various aggressive ways, and our people happened to be caught in one of those cases.”

South Korean Foreign Minister Cho Hyun said Wednesday, after meeting with Secretary of State Marco Rubio in Washington, that U.S. officials have agreed to let the detained workers return at a later point to finish their work on the site. The two countries also agreed to set up a working group to figure out a possible new visa category to make it easier for Korean companies to send workers to the U.S.

DHS and the State Department did respond to immediate request for comment.

The Associated Press contributed.