Approximately 300 South Korean citizens, detained nearly a week prior in an immigration raid at a Hyundai plant in Georgia, were anticipated to board a chartered flight on Wednesday to return to South Korea. However, a spokesperson for Hartsfield-Jackson Atlanta International Airport informed NBC News that the “charter flight has been canceled.”

The flight tracking website Flightaware shows the chartered Korean Air flight within U.S. airspace, yet the airport spokesperson could not confirm the plane’s landing status in Atlanta.

South Korean authorities expressed hope that the aircraft could depart Atlanta as soon as Wednesday afternoon local time, shortly after its arrival from Seoul. The detainees have been held in immigration detention in rural Georgia since their arrest in Ellabell on Thursday.

Nonetheless, the foreign ministry communicated early Wednesday that the departure was likely to be postponed since it “has become difficult due to circumstances on the U.S. side.”

“We are maintaining consultations with the U.S. authorities to expedite departure as soon as possible. Further notices will be provided once there are additional updates,” stated the ministry.

Secretary of State Marco Rubio is anticipated to meet with South Korean Foreign Minister Cho Hyun this morning at the White House, according to Rubio’s public schedule.

Immigration and Customs Enforcement referred questions on the latest developments to the White House, which did not immediately reply to NBC News.

The South Korean nationals were among the 475 people federal and immigration agents arrested last Thursday when they raided a construction site in Ellabell, where the South Korean companies Hyundai and LG Energy Solution were jointly building an electric vehicle battery plant.

Video released last week by Immigration and Customs Enforcement showed some of the South Korean nationals being shackled at the wrists and ankles before being placed in vans.

Steven Schrank, special agent in charge of Homeland Security Investigations in Georgia, categorized the raid as the largest single-site enforcement operation in the history of his agency.

According to Schrank and an ICE news release, the people arrested were working or living in the country illegally.

Of those detained, 47 were employed by LG Energy Solution and the rest were hired by subcontractors. Hyundai said none of those detained were directly employed by the company.

Most of the South Koreans detained were either engineers or working in after-sales services and installation, according to Atlanta-based immigration attorney Charles Kuck, who is representing at least seven of them. He added that many were doing work authorized under the various visa programs, allowing them to enter the U.S.

Sarah Park, president of the Korean American Coalition, said Monday that the detained workers should not be blamed for the challenges companies face in trying to secure the proper U.S. visas for employees who are key to getting new facilities up and running.

“I wish that Americans in America would be a little bit more sympathetic to what the Koreans have witnessed,” James S. Kim, chairman of the American Chamber of Commerce in Korea, said Wednesday in an interview with NBC News in Seoul. “And as long as they do that, I think the two countries can work together to kind of mitigate what had happened and move forward.”

South Korea, a key U.S. ally in Asia, has pledged $350 billion in U.S. investment in exchange for a lower tariff rate.

White House Press Secretary Karoline Leavitt said Monday that while President Donald Trump understands that companies “want to bring their highly skilled and trained workers with them, especially when they’re creating very niche products,” he also “expects these foreign companies to hire American workers.”

Federal authorities showed up at the Hyundai-LG plant last Thursday to execute a judicial search warrant in connection with what they said was a criminal investigation into allegations of unlawful employment practices. No criminal charges have yet been filed.

According to the warrant, agents were authorized to seize employment records and immigration documents as well as ownership and management records related to the construction site. Authorities were also looking for four individuals, but the reasons why the federal government was specifically interested in them remain under seal.

On Sunday, U.S. and Korean government officials reached a deal to release the workers from immigration custody and return them to their home country.

Consulate officials and other South Korean officials met with those detained at the Folkston ICE Processing Center over the weekend, Meredyth Yoon, a litigation director at Asian Americans vancing Justice-Atlanta, which has been assisting detainees and their families seeking legal help, told NBC News on Tuesday.

Yoon said that, as part of the deal, most of the South Korean nationals had agreed to “voluntary departure,” avoiding formal deportation orders.

The South Korean government said Tuesday that the Consulate General in Atlanta and officials from the Ministry of Foreign Affairs had provided “active consular assistance to our citizens detained” and assisted in “consultations with the United States necessary for the early repatriation of all our detainees via chartered flights.”

Yoon said about 175 of the remaining detainees — who hail from Guatemala, Colombia, Chile, Mexico, Ecuador, Venezuela and Japan — remain in immigration detention and that her organization is working on connecting the affected families to aid.