North Korea is reportedly having difficulties retrieving payments from foreign trade partners due to international financial sanctions on the communist country that were imposed after the North conducted a nuclear test in May of last year.

According to sources in China’s mine industry and companies trading with North Korea, Pyongyang has yet to receive four-point-six million U.S. dollars from Europe for zinc it exported last year due to the sanctions.

An insider of the Chinese mine industry says that even some Chinese banks have refused to transfer money to North Korea for exports.