ANKARA 

North Korea affirmed the "absolute solidity" of its alliance with Russia on Thursday as it marked the first anniversary of the signing of their bilateral defense, state media reported.

The North’s mainstream daily Rodong Sinmun, which reflects the country's official position, issued the message in an article marking the anniversary of the signing of the Comprehensive Strategic Partnership treaty.

The treaty was signed last June 19 in Pyongyang between North Korean leader Kim Jong Un and Russian President Vladimir Putin.

Describing the pact as opening "a new chapter in the friendship" between North Korea and Russia, the daily said the two countries have "unsparingly shown the absolute solidity of the alliance relationship."

The treaty calls on one party to come to the aid of the other without delay if it comes under armed attack.

North Korea deployed around 14,000 troops to the Russian side in the war against Ukraine between last October and this February.

Rodong Sinmun described the engagement of North Korean troops in the Russia-Ukraine war as the "most exemplary" implementation of the treaty.

"It is an unwavering stance of the two countries' peoples to deepen militant friendship and achieve mutual prosperity and well-being," the newspaper said.

South Korea Thursday called on North Korea and Russia to halt their "illegal military cooperation" that claims to justify Pyongyang's troop deployment to Moscow, Seoul-based Yonhap News reported.

“We urge North Korea and Russia to immediately halt any unlawful military cooperation and underscore that their cooperation must strictly comply with UN Security Council resolutions and international law, and not undermine peace and security on the Korean Peninsula and beyond," a Foreign Ministry official said.

Seoul also called on Russia to play a "constructive" role in promoting peace and stability in the region.

In April, North Korea confirmed for the first time that it had sent troops to fight for Russia against Ukraine.

North Korea plans to send 1,000 combat engineers and 5,000 military construction workers to clear mines and restore infrastructure in Russia’s Kursk region, according to Russian Security Council Secretary Sergey Shoygu.

Shoygu met with Kim in Pyongyang on Tuesday, in his third visit to the North Korean capital since March.