North Korea's Kim Jong-un sends letter to Putin to mark Russia Day

North Korean leader Kim Jong-un has sent a congratulatory letter to Russian President Vladimir Putin in honor of Russia Day.

According to the North's state-run Korean Central News Agency on Thursday, in the letter, Kim called Russia a "brotherly" nation and said Pyongyang and Moscow share an "unbreakable comrade-in-arms" relationship.

The letter was delivered by North Korean Ambassador to Russia Shin Hong-chol to Russia's Foreign Ministry to mark Russia Day on June 12th, a national holiday marking the formation of the Russian Federation.

While North Korea's state media had traditionally released Kim's Russia Day letter without context since last year, the KCNA has also reported on the delivery process before publishing the full text.

South Korea's Ministry of Unification said it doesn't see any particular significance in the latest exchange, as it was just a routine congratulatory message sent annually.