Russia’s ambassador to North Korea recently met with the DPRK’s deputy minister of railways to discuss issues related to a joint-run coal transportation project, the Russian embassy in Pyongyang said on Tuesday.

Russia exports domestically-produced coal from North Korea’s Rason port, a project which has seen Russian companies invest in and upgrade the facility, as well as gain exemptions from the UN’s sectoral sanctions.

The coal shipments are transported along a purpose-built rail line from the Russian border to the North Korean port, and are overseen by a joint venture between the two countries called RasonConTrans.

“The Russian side noted