Kim Tae-hyo, principal deputy national security adviser, speaks during a briefing at the presidential office in Seoul, Aug. 18. Yonhap

Kim Tae-hyo, a key foreign policy aide to President Yoon Suk Yeol, suggested that a potential return of former U.S. President Donald Trump could weaken the U.S. security umbrella, in a rare expression of concern by a government official regarding the potential victory of the Republican candidate, analysts said Wednesday.

However, some of Kim's remarks about the U.S. elections, such as his assertion that Democratic nominee and U.S. Vice President Kamala Harris "may need more heavyweight advisers on her foreign policy team," could be seen as controversial, observers noted.

"If Trump is reelected, there is a possibility that the U.S. security umbrella may be weakened, as it may seek to discuss the costs associated with the deployment of strategic assets provided to us," Kim, the principal deputy national security adviser, said during a forum hosted, Tuesday, by The Sejong Institute, a Seoul-based think tank.

The remarks were made during his lecture on the theme of U.S. presidential elections and South Korea's foreign policy strategy.

Kim stressed that the trilateral cooperation framework established between South Korea, the U.S., and Japan during the 2023 Camp David summit will likely remain solid under a potential Trump administration.

Regarding North Korea, Kim suggested that Trump might be keen on holding another summit with North Korean leader Kim Jong-un. However, he anticipated a low possibility of Washington striking any surprising new deals with Pyongyang, given the significant decrease in Trump's expectations following the failed summit in Hanoi in 2019.

Republican presidential nominee and former U.S. President Donald Trump participates in a fireside chat during the Moms for Liberty National "Joyful Warriors" Summit, in Washington, Aug. 30. Reuters-Yonhap

The security adviser's lecture drew considerable attention, as he is widely regarded as the architect of Yoon's foreign policy.

His remarks, a rare instance of a senior official in the Yoon administration addressing the U.S. presidential campaign in detail, appeared to diverge from the government's official position that the South Korea-U.S. alliance remains steadfast despite changes in leadership.

In previous briefings and media interviews, Yoon and his aides have generally avoided discussing the U.S. elections in detail. They have specifically downplayed concerns that Trump might again insist on a substantial increase in Seoul's contribution to the cost of stationing U.S. Forces Korea (USFK) or threaten to withdraw the troops.

Park Won-gon, a professor of North Korean studies at Ewha Womans University, commented that Kim may have been a little too candid, but he said what needed to be said.

"As Trump and his aides have hinted multiple times, if elected, Republicans may seek to weaken the extended deterrence that has been strengthened under Biden," Park said. "With just two months left until the elections, the security adviser expressed publicly that our government is closely watching these comments and plans to take appropriate response to potential shifts in U.S. policy."

"Kim's remarks directly conveyed the existing concerns among South Korean officials regarding a potential Trump return. Trump has made some blunt comments about the alliance with South Korea and touted his friendly ties with Kim Jong-un during his campaign, which have at times unnerved Seoul officials," a local foreign policy analyst told The Korea Times on condition of anonymity.

Democratic presidential nominee and U.S. Vice President Kamala Harris speaks at North Western High School in Detroit, Mich., U.S., Monday (local time). Reuters-Yonhap

However, the analyst noted that some of the security adviser's comments might be perceived as inappropriate for a senior official.

"Even if these were his personal opinions, the straightforward remarks seem ill-suited for a senior government official, especially when the government should be engaging in low-key diplomacy with both Team Trump and Harris," he said.

"Particularly, his comments about Kamala Harris could be perceived as somewhat offensive."

Regarding the Democratic candidate, Kim expressed concerns during the lecture that her diplomatic and security advisers may lack charisma. He said, "The names of the advisers on her foreign policy and security team, as well as those advising on social issues, are unfamiliar."

Kim added, "When dealing with these individuals, I feel like I need to teach them," suggesting that it might take time for a potential Harris administration to carry out solid policy initiatives of its own.

It is unclear what Kim meant by "teach," but it could be interpreted as implying that Harris might lack experience with Korean Peninsula affairs compared to incumbent President Joe Biden or former President Barack Obama.