Pyongyang’s economic engagement with Moscow ranges from small enterprises to large schemes that help Russia more cheaply fulfill its goals. The U.S. State Department approximates that around 20,000 North Koreans are sent—most, forcibly—to work in Russia each year for Russian companies (some estimates say the number is as high as 50,000). North Korea’s largest money makers in Russia are in the fields of logging and construction. These workers live in “slave-like conditions,” are poorly fed and equipped, and only receive a small fraction of the salaries that they are due. The rest, allegedly, goes straight to Kim’s coffers.

According to James Hoare’s Historical Dictionary of the Democratic People's Republic of Korea, Russia has hosted North Korean labor camps since 1967, when the then-Soviet Union was shrinking its notorious gulag system. Many gulag camps had forced their prisoners to do hard, manual work; the arrival of North Koreans helped replace some of that cheap labor. These North Korean camps, which exist to this day, do the same kind of logging work in Siberia’s harsh, endless forests that their gulag predecessors once did.

North Korean construction workers toil in similarly miserable situations. They were spotted by Norwegian journalists working to finish the newly opened Zenit Arena in St. Petersburg that will be used during the 2018 World Cup. One worker told The Guardian that the men were earning money to help “facilitate the country’s defense.” German journalists have also found North Koreans working to repair and complete World Cup 2018 stadiums in Moscow and Ekaterinburg. Qatar, which will host the 2022 World Cup, has taken its lead from Russia and currently has 2,800 North Koreans working in part to build the infrastructure needed for the event.

In addition, there are a variety of small North Korean-owned businesses across Russia. These range from North Korean-owned, -operated, and -staffed restaurants in Russia’s far east, to small tourism operations. North Korea recently opened a travel agency in Russia to bring Russian tourists to North Korea, while a passenger and cargo ferry service between Vladivostok, Russia, and Rason, North Korea, was opened in May 2017. Russian businesses in Vladivostok often hire North Koreans to paint and decorate homes in their city.

While these workers may be the main conduit of Russian money into North Korea, Russia has aided the country in other ways. In 2014, it forgave 90 percent of the nearly $11 billion in debt that it (and the Soviet Union before it) was owed by North Korea. The remaining portion of the debt was to be repaid to Russia by deposits into an account that could then be used to grow Russian-North Korean ties and trade. To avoid the difficulties that western sanctions have placed on payments and financial transfers to North Korea, the two countries have an arrangement by which Russia pays Pyongyang in rubles.