More than 300 South Koreans who were detained in a massive immigration raid at a Hyundai plant in the US state of Georgia have arrived in their home country.

Their return comes as the country’s president and Hyundai’s chief executive have warned about the impact of the raid.

A chartered Korean Air jet carrying the workers and 14 non-Koreans who were also detained in the raid took off from Atlanta at midday local time on Thursday (17:00 BST). One South Korean national has reportedly chosen to stay in the US to seek permanent residency.

The departure was delayed by more than a day because of an instruction from the White House, South Korean President Lee Jae Myung said on Thursday.

President Donald Trump ordered the pause to check whether the workers were willing to remain in the US to continue working and training Americans, according to a South Korean foreign ministry official.

The BBC has contacted the White House for comment.

A large group of journalists had gathered at Incheon International Airport ahead of the workers’ arrival.

There were also a few people protesting the raid. One of them held up a banner showing Trump in the uniform of an immigration agent, with the caption: “We’re friends! Aren’t we?”

The returning workers have requested privacy, South Korea’s foreign ministry said earlier on Friday, advising media outlets to blur any photographs and videos so that they will not be identified.

Companies would be “very hesitant” about investing in the US following the raid, South Korea’s president said on Thursday.

“The situation is extremely bewildering,” Lee added, while noting it is common practice for Korean firms to send workers to help set up overseas factories.

“If that’s no longer allowed, establishing manufacturing facilities in the US will only become more difficult… making companies question whether it’s worth doing at all,” he added.

Seoul is negotiating with Washington on visa options for South Korean workers “whether that means securing (higher) quotas or creating new visa categories”, Lee said.

On Friday, the South Korean foreign ministry said it had called for the US Congress to support a new visa for Korean firms.

During meetings with US senators in Washington this week, Foreign Minister Cho Hyun reiterated concerns among South Koreans over the arrests, the ministry said in a statement.

Meanwhile, Hyundai’s chief executive José Muñoz has said the raid will delay the factory’s opening.

Mr Muñoz told US media that the raid will create “minimum two to three months delay (in opening the factory) because now all these people want to get back”.

Last week, US officials detained 475 people – more than 300 of them South Korean nationals – who they said were working illegally at the battery facility, one of the largest foreign investment projects in Georgia.

LG Energy Solution, which operates the plant with Hyundai, said that many of its employees who were arrested had various types of visas or were under a visa waiver programme.

A worker at the plant spoke to the BBC about the panic and confusion during the raid. The employee said the vast majority of the workers detained were mechanics installing production lines at the site, and were employed by a contractor.

South Korea, a close US ally in Asia, has pledged to invest tens of billions of dollars in America, partly to offset tariffs.

Media in the country have described the raid as a “shock,” with the Dong-A Ilbo newspaper warning that it could have “a chilling effect on the activities of our businesses in the United States”.

The Yonhap News Agency published an editorial on Thursday urging the two countries to “cooperate to repair cracks in their alliance”.

The timing of the raid, as the two governments engage in sensitive trade talks, has raised concern in Seoul.

The White House has defended the operation at the Hyundai plant, dismissing concerns that the raid could deter foreign investment.

On Sunday, US President Donald Trump referenced the raid in a social media post and called for foreign companies to hire Americans.

The US government would make it “quickly and legally possible” for foreign firms to bring workers into the country if they respected its immigration laws, Trump said.

Additional reporting by Hosu Lee in Seoul