National Security Adviser Jake Sullivan speaks during a press briefing at the White House in Washington, D.C., Tuesday. EPA-Yonhap

By Kang Seung-woo

Quickly developing discussions between South Korea and the United States on declaring a formal end to the Korean War appear to have hit a snag as Washington has made it clear that it cannot accept Seoul's proposal, at least at this time, according to diplomatic observers, Wednesday.

Since President Moon Jae-in once again floated the idea in a United Nations General Assembly speech in September, it has been gaining traction, as evidenced by six meetings occurring between South Korea's top nuclear envoy Noh Kyu-duk and his U.S. counterpart, Sung Kim, since August.

However, National Security Adviser Jake Sullivan seems to have stepped on the brakes amid the Moon administration's push for an end-of-war declaration, Tuesday (local time).

"We may have somewhat different perspectives on the precise sequence or timing or conditions for different steps, but we are fundamentally aligned on the core strategic initiative here and on the belief that only through diplomacy are we going to really, truly be able to effectively make progress and that that diplomacy has to be effectively paired with deterrence," Sullivan said during a press briefing.

His remarks are in line with those of Kim following his latest meeting with Noh, Sunday.

At the time, the American envoy said that the U.S. will explore different ideas and initiatives, including Moon's end-of-war proposal, raising speculation that the two sides were not exactly on the same page.

"As South Korea is pushing to declare an end to the Korean War now, the U.S. appears to have drawn a line regarding signing a declaration right away," said Park Won-gon, a professor of North Korean Studies at Ewha Womans University.

"Considering the remarks by Sullivan and Kim, the allies remain apart over the end-of-war issue."

Park added, "The U.S. government is not opposed to ending the war, but their remarks indicate that the U.S. is not prepared to sign an end-of-war declaration at this time."

The U.S. stance is that North Korea should return to the negotiating table and in the process of nuclear talks, the end-of-war idea could be on the agenda, according to Park.

In response to Sullivan's remarks, a senior Korean government official said that South Korea and the U.S. will hold in-depth discussions on the issue, without elaborating on the U.S. national security adviser's comment.

While Seoul insists that the end-of-war declaration may help bring North Korea back to the dialogue table by offering some security assurances, some believe that it could undermine the legal basis for the stationing of U.S. forces in South Korea.

The U.S. currently maintains some 28,500 troops here.

North Korea has not responded to U.S. overtures since the Joe Biden administration took office in January, accusing the U.S. of harboring what it claims to be hostile intent toward Pyongyang. North Korea has also stayed away from direct, meaningful dialogue with the U.S. since early 2019.