North Korea appears to have decided to shut down some of its diplomatic missions, prompting speculation that the country is not able to maintain them due to economic difficulties amid international sanctions.

Multiple sources say North Korea's Foreign Ministry recently notified China of its decision to close the consulate general in Hong Kong, possibly to streamline the operation of overseas diplomatic establishments.

South Korea's Yonhap News Agency has reported that the North also conveyed its intention to close down its embassies in Uganda, Angola and Spain to the respective governments, according to local media reports and other sources.

North Korea has not made any announcements, but its state-run media reported on Monday that its ambassadors to Uganda and Angola had paid farewell courtesy calls to those countries' presidents.

Sources related to South Korea's Unification Ministry say North Korea has about 50 diplomatic missions worldwide.

The sources say the move to close down overseas missions appears to show it is no longer financially feasible for the North to maintain them due to strengthened sanctions.