A flight carrying more than 300 South Korean workers who were detained by US immigration authorities in Georgia last week will depart Thursday afternoon, according to a Korean government official familiar with the matter.

A Korean Air charter plane from Seoul landed in Atlanta Wednesday to help repatriate the South Korean citizens. The plane will arrive at South Korea’s Incheon International Airport on Friday afternoon

The South Korean citizens “won’t be wearing handcuffs or other physical restraints,” the Korean government official said.

While the workers will soon be on their way home, the impact of the detentions on US-South Korean relations – notably the countries’ deep economic ties – will likely reverberate well into the future, experts say.

South Korean Foreign Minister Cho Hyun, who met with US Secretary of State Marco Rubio on Wednesday, also requested support from the US to ensure the South Korean citizens could quickly depart the US and “receive no disadvantages for future visits to the US, since they are not criminals,” according to a statement from the ministry.

News of the detentions – including images released by ICE of workers being lined up and restrained with long chains – has sparked widespread frustration and outcry across the political spectrum in South Korea, a staunch and longstanding US ally that earlier this year pledged to invest hundreds of billions of dollars into the American economy.

“It’s really no way to treat your friends,” Cho Hee-kyoung, a law professor at Seoul’s Hongik University, told CNN, calling the Trump administration’s monthslong investigation and subsequent raid at the factory a “surprise.”

South Korea’s government announced Sunday that an agreement had been reached with US officials to release the Korean workers, but the details were still being finalized.

The State Department’s readout of the meeting between Rubio and Cho did not mention last week’s detention of Hyundai workers but did state, “The Secretary said the United States welcomes ROK investment into the United States and stated his interest in deepening cooperation on this front.”

The workers were taken into custody last Thursday during a sweeping ICE operation at a battery plant under construction in Ellabell, approximately 25 miles west of Savannah. The plant is a joint venture between Hyundai and LG Energy Solution, two giants of South Korean industry that have made major investments in the US.

Outcry from an ally

South Korea has long been one of the United States’ closest allies and is its sixth-largest trading partner. Many fear the detentions of hundreds of workers from the country could have a chilling effect on any business thinking of striking a deal on US soil.

Since the ICE raid on September 4, Seoul –– which has a deeply ingrained protest culture –– has not seen any large-scale demonstrations against the US. Small protests have been seen, but any outcry has largely played out elsewhere.

Newspaper opinion columns and social feeds have reached similar conclusions: True partnership between the two countries means not putting Koreans sent to the US in chains –– people sent across the ocean to help the US thrive.

The conservative paper Chosun Ilbo reported growing calls from the South Korean business community for the government to “formally sit down at the negotiating table with the US and secure visa quotas for Korean skilled workers, ensuring treatment that matches the scale of our investments there.”

The more middle-of-the-road paper Hankook Ilbo warned of the “Trump risk” Korean investors face, even after the announcement of a deal to free the detained workers

In a column titled “Is this any way for the US to treat an ally?” from the left-leaning outlet Hankyoreh, editors of the paper condemned the Trump administration for “double-dealing” with Seoul.

“The US’ double-dealing behavior of demanding massive infusions of capital from Korea, only to use immigration raids to intimidate the companies making these investments, is extremely regrettable,” the paper noted.

“It was like ‘a slap in the face’ moment,” Choi Jong Kun, South Korea’s former First Vice Foreign Minister, told CNN.

“Those plants didn’t have to be built there. They were built because the US wanted them,” he added. “And yet to say Korean workers must be replaced with American workers for facility construction – I see that as completely out of touch with reality.”

Choi emphasized the temporary nature of South Koreans’ work to set up factories in the US: “They have no intention to stay.”

Questions about visa status

It has been common practice for South Korean nationals to perform this type of work at US plants and factories, but the battery plant raid seems to reflect a different enforcement of visa rules, said Cho, the law professor.

Cho said South Korean workers have long worked under visa arrangements similar to those detained in Georgia and pointed to the ongoing problem of the US approving too few business visas.

“Although it wasn’t strictly in compliance with the rules and regulations, everybody basically had turned a blind eye to it because of the shortage of H1 visas,” Cho said, referring to longer-term US business visas.

Lawyers for some of the detained workers insist their clients were legally working on the Georgia site.

Immigration attorney Charles Kuck told CNN that two detained workers he’s representing were authorized to work under a visa waiver. One arrived in the US near the end of August, and the other arrived several weeks ago, Kuck said, noting both are engineers who came to the US “to advise briefly on the work” being done at the site.

Kuck said his clients “had a specific time they were going to be here and leave, for a specific task that they were assigned to do here as part of their company’s contract with Hyundai.”

Some US lawmakers have recently pushed to address the lack of visas for South Korean workers. A bill called the “Partner with Korea Act” was introduced in the House in July by California Rep. Young Kim, a Republican.

The bill would carve out “15,000 E-4 highly skilled work visas for Korean nationals with specialized education or expertise, provided that potential employers ensure the visa holders are not hired for positions that American workers could fill,” according to a statement about the bill from Kim’s office.

The bill hasn’t moved in the House since being referred to the Judiciary Committee after it was introduced.

Pending business

South Korea still has major unfinished business with Washington. In July, President Donald Trump announced a sweeping new trade deal that includes $350 billion in investments in the US by South Korea, but the details are still being worked out.

The aim of the agreement, CNN Senior Business Writer Allison Morrow wrote in a Tuesday analysis, is largely to create more jobs for Americans –– but that’s not so simple.

“Companies often want to – or even need to – bring in their own workers to set up shop, install proprietary equipment, and train the less-skilled hourly employees who’ll be running things day to day,” Morrow wrote.

Chang Sang-sik, head of research at the Korea International Trade Association, told the Financial Times that the US government was acting “two-faced.”

“It is asking Korea to invest more in the US, while treating Korean workers like criminals even when it is well aware that they are needed for these projects to happen,” Chang said.

On Tuesday, South Korean President Lee Jae Myung called the detention of workers in Georgia “unjust infringements on the activities of our people and businesses” and said he hopes such practices “will not happen again.”

But reacting with indignation has not been an option for Lee. Instead, his administration has stressed efforts to rapidly diffuse the situation.

South Korean officials are acutely aware of the US defense presence within the South’s borders. Approximately 28,500 American troops are stationed across South Korea, a protective force against neighboring nuclear-armed North Korea. (CNN)