President Yoon Suk Yeol gives a prerecorded public address from his office in Yongsan District, Seoul, Thursday. Courtesy of presidential office

The Korean public was not the only one frustrated by President Yoon Suk Yeol's address on Thursday, in which he justified his short-lived imposition of martial law as an "attempt to protect the nation's democracy" and accused his political opponents of being "monsters."

The speech also drew ire from China.

During the 29-minute address, Yoon referenced two cases involving Chinese nationals who were caught filming Korea's security facilities, saying these actions posed a threat to national security. He also stated that "Chinese-made solar power facilities will destroy forests across the country."

The Chinese government, which has so far refrained from commenting on Korea's martial law turmoil, immediately protested against Yoon's remarks.

"We are surprised by those comments and find them deeply upsetting. We absolutely oppose the ROK side associating its domestic affairs with Chinese elements, amplifying unfounded 'Chinese spy' accusations and throwing mud at normal economic and trade cooperation," Chinese foreign ministry spokesperson Mao Ning said during a briefing later in the day. ROK stands for the Republic of Korea, Korea's official name.

Mao Ning, spokesperson for China's Ministry of Foreign Affairs, gestures during a press conference in Beijing, Monday. EPA-Yonhap

She also said the Korean authorities have yet to make a conclusion regarding the particular cases mentioned by the president.

"None of these are conducive to a healthy and steady China-ROK relationship," Mao added.

The fact that the Chinese nationals in question remain under investigation, and have yet to be formally indicted, raises questions about the appropriateness of Yoon mentioning these cases in a public speech.

With his bold remarks, Yoon risks straining Korea-China relations once again, just as they have been showing signs of recovery following years of being strained.

Visits by high-level officials and people-to-people exchanges between the two nations have increased recently. China's surprise decision in November to exempt Korean nationals from visa requirements for stays of up to 15 days — the first such measure in over 30 years of bilateral relations — was widely seen as a gesture aimed at improving ties.

This warming of ties has led to anticipation that Chinese President Xi Jinping might visit Korea to attend the 2025 Asia-Pacific Economic Cooperation summit in Gyeongju, which, if it happens, would be his first trip to Korea in more than a decade.

However, the prospect of Xi's visit is now uncertain due to the political unrest in Korea.

U.S. President-elect Donald Trump speaks at a reception at the New York Stock Exchange after being named TIME's Person of the Year, Thursday. AFP-Yonhap

Who will deal with Trump?

During his address, Yoon made it clear he had no intention of stepping down. The embattled president, whose approval ratings have hit record lows, said, "I will fight with you, the people, until the last moment."

Yoon's decision to cling to power raises concerns about Korea's standing on the diplomatic stage, including its relations with its key ally, the United States.

While U.S. allies worldwide are scrambling to establish ties with the incoming Donald Trump administration, Korea's diplomatic engagement with Trump seems limited amid the waning leadership of Yoon.

Victor Cha, Korea Chair at the Center for Strategic and International Studies (CSIS), described the current situation in Seoul as "the worst-case scenario."

"In many ways, this is probably the worst-case scenario for the start of Trump 2.0 and the U.S.-Korea alliance. Of course, there are people who will try to continue the connections. But the reality is that Trump is Trump, and the personal, leader-to-leader tie is very important," Cha said during a recent CSIS podcast.

He further noted that the decisions Trump makes within his first 100 hours in office — not 100 days — could have significant repercussions for Seoul.

Meanwhile, according to Japanese media reports, Akie Abe, widow of former Prime Minister Shinzo Abe, plans to travel to the U.S. this weekend in hopes of meeting with Trump.

This situation is reminiscent of the early days of Trump's first term when Korea was mired in political turmoil under former President Park Geun-hye, who was ousted in March 2017. While Park was going through impeachment proceedings, then-Japanese leader Abe built a rapport with Trump through high-profile meetings, including golf outings.

Yoon reportedly took up golf recently to foster a similar relationship with Trump.

But now, it is unclear whether he can even arrange a meeting with the incoming U.S. leader, let alone survive the parliamentary vote on his impeachment motion set for Saturday.

Foreign Minister Cho Tae-yul, who was present at a Cabinet meeting held approximately an hour before Yoon declared martial law on the night of Dec. 3, strongly opposed the president's decision. Cho must have foreseen the consequences Yoon's declaration would have for Korea's diplomacy.

The fallout is already evident, and the road to recovery appears daunting.