Acting president Choi Sang-mok speaks during a disaster management meeting at the Government Complex building in Seoul on Tuesday. (Yonhap)
Acting president Choi Sang-mok speaks during a disaster management meeting at the Government Complex building in Seoul on Tuesday. (Yonhap)

Acting President Choi Sang-mok vowed to address security challenges on the Korean Peninsula by strengthening cooperation with South Korea's allies and partners, including the United States and Japan, in his New Year's speech on Tuesday.

Choi, who is also South Korea's deputy prime minister and finance minister, said the joint defense posture between South Korea and the US will remain ironclad, capable of countering North Korea's nuclear threats and military cooperation between Pyongyang and Moscow.

"South Korea's armed forces have established a strong security posture," Choi said. "The South Korea-US alliance, the trilateral cooperation between South Korea, the US and Japan, as well as solidarity with our allies and partners will remain unperturbed and become stronger."

Choi added the government will put its utmost effort into stabilizing state affairs in the fields of national defense, foreign affairs, economy and social affairs, as the rapidly changing trade environment, uncertainties in international security and the ongoing instability in the domestic political landscape are "adding to the people's concerns."

In this vein, the South Korean government will work to address challenges in the fields of foreign affairs, security and trade, arising from US President-elect Donald Trump's inauguration in January.

"I will closely communicate and coordinate with major partners to ensure South Korea's safety and to serve our national interests," he said.

Choi also expressed deep condolences to the bereaved families of the victims of Sunday's plane crash in Muan, South Jeolla Province, which killed 179 in the worst-ever aviation disaster on South Korean soil. He said the government will work sincerely to aid the families, identify the causes of the incident, and take measures to prevent such an tragedy from recurring.

Choi has served as acting president since Han Duck-soo -- who had assumed the role after President Yoon Suk Yeol's impeachment on Dec. 14 -- was also impeached on Friday.