DETROIT (Reuters) -The head of LG Energy Solution's North American business said on Tuesday the battery maker is hopeful about negotiations around visas for its workers following a massive raid on its joint-venture plant with Hyundai in Georgia.

"We're cautiously optimistic that this type of thing will not happen again," said Robert Lee, president for LG Energy Solution in North America.

The raid earlier this month by U.S. authorities led to the arrest of about 475 workers, and set the battery plant at the site back at least two to three months, Hyundai's CEO said last week. Many of those workers returned to Korea last week. 

"We feel really bad for all of our workers as well as our subcontractors who came here on business to install equipment and they were detained," Lee added, speaking at an automotive conference in Detroit.

Reuters previously reported that workers at other LGES production sites went home after the raid because of visa concerns.

Lee reiterated what the CEO of LGES previously stated: production across its facilities would not be meaningfully affected by these changes.

"We have to try to find a plan that works, regardless of various different scenarios. That's what we're doing," Lee said on the sidelines of the event.

In the wake of the raid, Washington and Seoul have agreed to discuss establishing a new visa category for Koreans, South Korean Foreign Minister Cho Hyun has said.

It is typical for automotive complexes to bring on droves of workers to install equipment, especially for battery plants, where the suppliers have expertise. Lee said he is encouraged by the U.S. and Korea's discussions to improve that cumbersome visa approval process.