North Korean leader Kim Jong-un / Yonhap

North Korean leader Kim Jong-un received a message stressing bilateral relations from the head of the Russian-backed Donetsk People's Republic, Pyongyang's state media said Wednesday.

In the letter, Denis Pushilin, leader of the breakaway entity in eastern Ukraine, extended his "heartfelt congratulations" to Kim on the occasion of Korea's liberation anniversary on Aug. 15, the official Korean Central News Agency (KCNA) said.

"The message said that the past history of the Korean people was filled with trials and there were many difficulties on the road to freedom, but the Korean people overcame them bravely and proudly," according to the KCNA.

Pushilin added that the "people of the Donbas region, too, are fighting to regain their freedom and justice of history today just as the Korean people did 77 years ago."

The message then "expressed the conviction that an equally beneficial bilateral cooperation" will be achieved between Donetsk and the North.

Last month, North Korea formally recognized the independence of the pro-Russian separatist republics of Donetsk and Luhansk in Ukraine, becoming the third country in the world to do so after Russia and Syria.

Pyongyang has recently stressed its close ties with Moscow amid chilled inter-Korean ties and stalled nuclear talks with Washington. (Yonhap)