Seoul,  North Korean leader Kim Jong-un expressed his country's "firm solidarity" with Russia in a congratulatory message sent to President Vladimir Putin over Moscow's celebration of its "Victory Day" holiday, Pyongyang's state media reported on Tuesday.

In the message sent the previous day, Kim congratulated Putin on the anniversary of the Soviet Union's victory over Nazi Germany in World War II, the North's official newspaper Rodong Sinmun and the Korean Central News Agency (KCNA) said.

Russia celebrated the 77th anniversary of the holiday on Monday.

Kim's message "extended firm solidarity to the cause of the Russian people to root out the political and military threat and blackmail by the hostile forces and safeguard the country's dignity, peace and security", Yonhap News Agency quoted the KCNA as saying in an English-language article.

"It expressed belief that the strategic and traditional relations of friendship between the two countries would steadily develop in conformity with the requirements of the times," it added.

The North has recently highlighted its traditional ties with Russia, which has drawn condemnation from many countries for its invasion of Ukraine.

In February, a spokesperson for the North's Foreign Ministry blamed the Ukraine crisis on the "hegemonic policy" of the US and the West.