Kim Gunn, South Korea's top nuclear envoy, said North Korea's plan of severing inter-Korean exchanges would only hurt itself, as he attended a meeting with his counterparts from the United States and Japan in Seoul on Thursday to address a laundry list of urgent security issues.

"Most recently, North Korea announced the plan to abolish agencies for inter-Korean exchanges. It also clings to the old playbook to shift blame to the ROK and the US," Kim said, referring to South Korea's official name, the Republic of Korea.

"All these are aimed at insulating itself from the outside world. It is a North Korean version of 'closed-door policy.' Such anachronistic attempts, however, will only hurt North Korea itself."

The top nuclear envoys of South Korea, the United States and Japan discussed a wide range of contentious issues from illicit arms transfers between North Korea and Russia to the Kim Jong-un regime's overtly belligerent words and actions targeting South Korea.

The trilateral meeting, the first of its kind since last October, sought to strengthen coordination in responding to the multifaceted challenges at hand.

"Today's meeting well represents the solidness of the trilateral cooperation founded upon what our leaders agreed in Camp David," Kim said in his opening remarks. "We will tirelessly enhance our efforts to block North Korea's illicit activities."

The meeting took place at an especially critical juncture, just two days after the publicly disclosed talks between Russian President Vladimir Putin and North Korea's Foreign Minister Choe Son-hui in Moscow. The interaction was an apparent choreographed display of their intent to intensify alignment, including military cooperation that poses challenges to established international rules and order.

"Kim Jong-un may be banking on its unlawful military cooperation with Moscow. This will only lead to a dead end. It will simply confirm North Korea's reputation as a blatant offender of international rules and norms," Kim Gunn said.

"The world will never condone North Korea's destabilizing behaviors that threaten international peace and security."

The three nuclear envoys criticized North Korea's transfers of its weapons and materials to Russia, which flagrantly violate multiple UN Security Council resolutions and support Russia's war of aggression.

"We also need to closely monitor what Russia might provide to North Korea in return for these arms exports," said Hiroyuki Namazu, director general for Asian and Oceanian affairs at the Japanese Foreign Ministry.

"In the face of these events, our three countries have firmly responded together, including issuing the ministerial joint statement, condemning Russia's use of ballistic missiles procured from North Korea against Ukraine."

The three envoys also expressed concerns over North Korea's recent saber-rattling and shelling provocations specifically directed at South Korea.

Early this month, North Korea fired around 350 shells toward the inter-Korean western maritime border over three consecutive days.

Such belligerence came after North Korean leader Kim Jong-un's public declaration of "hostile relations between the two countries" during his year-end party plenum.

At Monday's parliamentary meeting, Kim also directed the inclusion of his regime's objective of the full-scale occupation of South Korea in the event of war on the Korean Peninsula and designation of South Korea as the "primary foe and invariable principal enemy" in the country's constitution.

"The United States is also deeply concerned by the recent uptick in hostile rhetoric, particularly toward the Republic of Korea from the DPRK regime. Such rhetoric is unnecessarily increasing tensions on the Korean Peninsula," said US Senior Official for North Korea Jung Pak.

The DPRK refers to North Korea's official name, the Democratic People's Republic of Korea.

"The threat posed by the DPRK to regional and international peace and security remains an issue of extraordinarily high concern for the United States," Pak added.

Pak also underscored that the three countries have a laundry list of issues to address. The matters encompass North Korea's continuing development of its unlawful nuclear and ballistic missile programs, its transfer of ballistic missiles and other weapons to Russia for use against Ukraine, its ongoing malicious cyber activities against countries around the world and its continuing human rights violation.

"All of this demands our attention and coordinated action," Pak said.

The trilateral meeting followed separate bilateral discussions between Kim and his Japanese and US counterparts on Wednesday afternoon and Thursday morning, respectively.

Kim and Pak committed to "resolutely respond to the illicit cooperation between Russia and North Korea, which poses a serious threat to international security, including the Korean Peninsula, in coordination with the international community," South Korea's Foreign Ministry said in a statement.

"In this context, both sides shared assessments on the recent developments in relations between Russia and North Korea, including Foreign Minister Choe Son-hui's visit to Russia, and committed to engaging in close discussions on how to respond going forward."