A massive immigration raid at a Hyundai plant in the US will delay its opening by at least two months, according to the company.

The raid has raised tensions between the US and South Korea, where many of those detained were from, with the South Korean president warning that it will discourage foreign investment into the US.

South Korean officials have said many of the workers had been sent to the US factory temporarily to help get it going.

Hyundai chief executive José Muñoz told US media the raid will create "minimum two to three months delay [in opening the factory] because now all these people want to get back".

The raid in the state of Georgia was the biggest in US history, leading to the detention of 475 people, including roughly 300 people from South Korea.