The U.S. Department of Energy (DOE) officially announced on the 15th that South Korea has been classified as part of the 'Sensitive and Other Designated Countries List' (SCL). The designation was made by the Biden administration in early January, just before the Trump administration took office.
On the 15th, a spokesperson for the Department of Energy, Ben Dietrich, noted, "The U.S. government added South Korea to the lowest category of sensitive countries (other designated countries) in early January." The Department of Energy stated, "Being included on this list does not necessarily mean that there are adversarial relations with the United States, and many countries designated on the SCL regularly cooperate with the U.S. on various energy, science, technology, counterterrorism, and nonproliferation issues."
It also stated, "There is no restriction preventing Americans or DOE employees from visiting or doing business with the designated countries, nor does it prohibit citizens of those countries from visiting the DOE, and technological cooperation is also not prohibited; however, visits and cooperation must undergo prior internal review."
It added that "there are no new restrictions on bilateral scientific and technological cooperation with South Korea, so the Department of Energy hopes to enhance mutual benefits through cooperation with South Korea."