MOSCOW, September 9 (RIA Novosti) - Russian Prime Minister Vladimir Putin congratulated North Korea on Wednesday on the 61st anniversary of the communist state's founding.

The anniversary is one of the main state holidays in North Korea, along with the birthday of the "great leader" Kim Il-sung and that of his son, current leader Kim Jong-il.

In a message to Premier Kim Yong-il, Putin said: "It is with pleasure that I note the successful development of cooperation between Russia and the DPRK [the North's official name] in many areas."

He said the further strengthening of North Korean-Russian ties is "in the interests of the peoples of our countries, and in maintaining peace and stability in northeast Asia."

Russia has consistently maintained cordial ties with North Korea, and in recent years has joined China in resisting harsh sanctions against Pyongyang over its nuclear and ballistic tests. However, Moscow joined international criticism against the North after its second nuclear test blast in May.