Industry Minister Ahn Duk-geun speaks to reporters at Incheon International Airport, Thursday, before departing for Washington, where he will meet with U.S. industry and energy officials. Yonhap

Although the U.S. government maintains that designating Korea as a "sensitive country" in the energy sector will not impact bilateral cooperation, experts caution that the rare move to place a key ally on the list could disrupt future collaboration and harm Korea's reputation over time.

Scientists also worry that U.S. institutions may scale back funding for joint research and development with Korea in advanced technologies.

In January, the U.S. Department of Energy (DOE) decided to add Korea to its list of "sensitive" and other designated countries — alongside existing countries such as China, Russia, India and Pakistan —effective April 15.

Government officials in Seoul are scrambling to overturn the decision through diplomatic negotiations.

"The United States greatly values the close relationship we have with the Republic of Korea on scientific research collaboration, and we look forward to continued robust cooperation," U.S. Department of State spokesperson Tammy Bruce said during a briefing on Wednesday (local time).

Despite reassurances, the designation is expected to complicate research cooperation, experts say.

For instance, visiting research institutes or facilities under the U.S. National Nuclear Security Administration will now require access requests to be submitted at least 45 days in advance. Previously, researchers could access nonsensitive information without prior approval, but they must now undergo mandatory background checks.

"This isn't just about stricter protocols. The fact that intelligence authorities are monitoring Korean researchers and government officials will make American institutions hesitant to engage in joint projects," said Lee Chun-geun, an honorary fellow at the Korea Institute of Science & Technology (KIST) Evaluation and Planning.

A U.S. flag and the flag of the U.S. Department of Energy fly outside its building in Washington, Tuesday (local time). AFP-Yonhap

Lee also warned that even if Korea is eventually removed from the list through diplomatic efforts, the repeated designation could leave a lasting impact on its scientific community. Korea was previously placed on the DOE's list in 1981 and removed in 1994 after diplomatic negotiations.

Data from the Ministry of Science and ICT shows that Korea and the DOE have multiple joint research initiatives in key fields, including synthetic biology, secondary batteries, nuclear fusion and nuclear power. These collaborations involve joint research, regular conferences and participation in global forums.

A bilateral conference on synthetic biology is scheduled to take place in Illinois in the second half of this year, according to the ministry. Additionally, the KIST has been conducting joint studies on secondary batteries with the DOE's Argonne National Laboratory since May last year.

"DOE-affiliated research institutions may find it more difficult to secure funding for joint research with Korea in the future. Additionally, this could be used as a basis for U.S. to tighten export controls, adding dual-use materials to its control list for Korea," said Jun Bong-geun, head of the Korea Nuclear Policy Society.

The science ministry reaffirmed that bilateral cooperation remains unaffected.

"We have confirmed that there has been no impact on our cooperation with the U.S. Department of Energy so far, and we will continue to work closely on this matter," the ministry said in a statement.

A ministry official told The Korea Times that Science Minister Yoo Sang-im is reviewing a potential visit to the U.S., although a timeline has yet to be set.

Amid these developments, Industry Minister Ahn Duk-geun departed for Washington on Thursday to push for Korea's removal from the list, with meetings scheduled with U.S. energy officials.

However, uncertainties remain over how Seoul can persuade Washington to reverse the decision, as it is still unclear why Korea was added in the first place.

According to Korean authorities, the designation was not based on foreign policy concerns but rather on security-related issues tied to DOE research institutions. A similar explanation was provided by acting U.S. Ambassador to Korea Joseph Yun.

Korean officials say they have not been given specific details about the security concerns.

"We've been discussing with affiliated laboratories to look into specific security breach cases that may have affected the listing, but nothing has been found yet," the science ministry official said.