South Korean President Yoon Suk Yeol is slated to begin a six-day visit to New York starting Monday to attend the 78th United Nations General Assembly, which comes after a summit on Wednesday where North Korea leader Kim Jong-un offered his full support to Russia's "sacred fight" against the West.

During his visit, Yoon is likely to issue warnings regarding increasing military activities between North Korea and Russia, as well as Pyongyang's evolving nuclear ambitions.

At the assembly, with this year's theme being "Rebuilding Trust and Reigniting Global Solidarity," Yoon will deliver a keynote speech Wednesday, according to the presidential office on Thursday. He will announce plans to serve as a nonpermanent member of the UN Security Council for the 2024-2025 term.

In the wake of the summit between Kim and Russian President Vladimir Putin where they discussed strengthening cooperation across various fields, including arms trade, Yoon is expected to address “an appropriate analysis and message concerning the military exchange” between the two countries, a high-ranking official from the presidential office told reporters Thursday on condition of anonymity.

"The president believes that words and actions in the international community should carry dignity, encompassing an accurate message and our intentions," he said. "He will address this from the perspective of Korea's national interests and in consideration of the regional allies in the Indo-Pacific."

He added that Yoon is expected to convey a message that leaders in the international community, who share common morals and norms, would agree with.

Regarding the North Korea-Russia summit, the official said, "We are closely monitoring and analyzing the current developments and potential outcomes." He anticipated that Kim would visit two other cities in Russia and tour military-related facilities on Friday and Saturday.

The official said that because Kim’s visit is still underway, the Korean government cannot ascertain the outcomes yet, but added, "We are closely monitoring and analyzing all preparation processes, developments and potential results."

Asked whether the government had confirmed suspicions that North Korea's rockets are being supplied to Russia, he said it was difficult to provide a definitive answer due to the security implications. "However, we have known for a long time that weapons supplied by North Korea are utilized by Russia and deployed on the battlefield in Ukraine," he said.

Asked if the government's policy of not supplying lethal aid to Ukraine might change in light of the North Korea-Russia summit, he responded shortly: "No."

The official said that the Korean government's support plan for Ukraine is "the first package of assistance, developed through careful consideration and discussion on how Korea can best provide much-needed help to Ukraine."

"It would not be normal for Korea's position to change abruptly within a day or two simply due to the actions of certain surrounding forces," he said.

Asked if the Korean government is considering developing its own nuclear armament in response to security threats from North Korea, he denied such a notion, saying, "We are utilizing nuclear power for economic and peaceful purposes."

Regarding increasing demands for a revision of the Korea-US nuclear energy agreement to allow Korea to reprocess spent nuclear fuel and stockpile uranium like Japan, he said he believed it would be “extremely unreasonable” to negotiate a new Korea-US nuclear energy agreement.

He added that the Korea-US nuclear energy agreement, signed in 2015, had already been revised following several years of negotiations. He added that it would be challenging to amend this agreement, which has a validity period of 20 years.

At this point, it is extremely unreasonable to pull out all the provisions on nuclear energy that were negotiated between Korea and the US and reinterpret them, the official said. “It is especially impossible to discuss with the US the issue of processing nuclear fuel necessary for nuclear armament on the premise of high enrichment of nuclear fuel.”

During President Yoon's visit to the UN General Assembly next week, he is anticipated to engage in more than 30 bilateral discussions to promote Busan as the site of the 2030 World Expo, according to Kim Tae-hyo, the deputy national security director.

The president plans to hold summits with over 30 countries, including North Macedonia, San Marino, St. Lucia, Mauritania, Monaco, Lesotho, Central African Republic, Thailand and Nepal, to solicit their support for the Busan Expo. Kim said there would be more bilateral summits as the government is still coordinating meetings.

Yoon's schedule will commence with a lunch with Ghanaian President Nana Akufo-Addo on Tuesday. Later, he will meet with United Nations Secretary-General Antonio Guterres to discuss cooperation between South Korea and the UN, as well as global issues including the conflict in Ukraine and collaborative efforts to address North Korean provocations. In the evening, Yoon and first lady Kim Keon Hee will attend a reception hosted by US President Joe Biden.

On Thursday, Yoon will attend the Digital Vision Forum hosted by New York University and unveil the Digital Bill of Rights, which outlines the foundational direction for a new digital normative order. He also plans to emphasize the importance of solidarity and cooperation within the international community to foster a society where digital prosperity is shared by all.

The following day, he will have a luncheon with leaders from the Pacific islands region and the secretary-general of the Pacific Islands Forum to continue building momentum for cooperation among the leaders, as established at the Korea-Pacific Islands Summit held in June.