The expert: This is why Russia buys weapons from North Korea

A US official, who spoke on the condition of anonymity, says that the purchase indicates that "the Russian military continues to suffer from severe supply shortages in Ukraine, in part due to export controls and sanctions," AP writes.

North Korea and Russia have grown closer over the past year.

In July, for example, North Korea became the only country in the world apart from Russia and Syria to recognize the independence of the breakaway regions of Donetsk and Luhansk in eastern Ukraine.

"Effect of bad planning"

According to Rein Pella, artillery expert and teacher at the Norwegian Defense Academy, the purchase is above all an effect of poor planning on the Russian side.

- You may no longer have factories that can manufacture ammunition in that amount, he says.

Hear from artillery expert Rein Pella about why Russia buys weapons from North Korea in the clip above.