Russia-North Korea ties developed into 'indestructible, genuine' relationship: Kim Jong-un

North Korean leader Kim Jong-un has said that his country's ties with Russia have developed into an “indestructible, genuine relationship between comrades-in-arms and alliance.”

Kim made the remarks in a congratulatory message he sent to Russian President Vladimir Putin on the eve of Russia Day, according to the Korean Central News Agency (KCNA).

Russia Day, which falls on June 12, marks the 1990 adoption by the Russian parliament of the declaration of state sovereignty of the Russian Federation.

The message also came ahead of the first anniversary of the signing of a mutual defense treaty between the two leaders in June last year, which calls for providing military assistance "without delay" if either side comes under attack.

Kim said the friendship between Moscow and Pyongyang has been further "cemented" due to the military comradeship the two nations' troops have forged "at the cost of their blood" during the Russia-Ukraine war.

Vowing to "stand with" Russia and its people, the North Korean leader further said his country has an "unshakeable" will to steadfastly develop the bilateral ties between the two countries.

Since October last year, North Korea has sent around 15,000 troops to Russia to fight alongside Russian forces against Ukraine, the Seoul-based Yonhap news agency reported.

In April, North Korea confirmed for the first time that it sent troops to Russia to support Moscow in its war against Ukraine under a mutual defense treaty.