From Angola to Hong Kong, North Korea is rapidly shuttering its overseas embassies, as Pyongyang's economy sputters and leader Kim Jong Un embraces 'new Cold War' diplomacy with Russia, experts say.

North Korea's state media has in the last week announced "farewell visits" by its ambassadors to African allies Uganda and Angola, and closed up shop in Hong Kong and Spain, local authorities said, with experts warning more such diplomatic departures are likely.

The last time the nuclear-armed country dropped diplomatic missions on this scale was in the mid-to-late 1990s when the country was hit by a famine in which hundreds of thousands of people died — estimates range into the millions.