Russia's diplomatic mission to North Korea complained on Thursday of acute shortages of essential goods such as medicine, problems getting health care and pandemic restrictions that it said were unprecedented in their severity.

Foreign diplomats have been leaving North Korea in droves, it said in a statement on Facebook, describing it as an exodus that had left behind fewer than 290 foreign nationals in the country.

"Those leaving the Korean capital can be understood," it said.

"Far from everyone can endure the total restrictions that are unprecedented in their severity, the acute shortage of essential goods, including medicine, the lack of opportunities to resolve health problems," it said.

North Korea has imposed crippling border closures to combat the pandemic, banned most international travel and severely restricted movement inside the country.

Only nine foreign ambassadors and four charges d'affaires were still representing their nations, with most embassies having cut staff to a minimum, Russia's diplomatic mission said.

Britain, Brazil, Germany and several other countries have already locked up the gates to their missions, while all foreign staff at international humanitarian organizations have left, it said.

"One thing is clear – unfortunately (the latest group to leave) will not be the last; the exodus of foreigners will continue," it said.

Last month, a group of Russian diplomats and family members used a hand-pushed rail trolley to leave North Korea amid tough restrictions including the blocking of most forms of passenger transport across the border.

Photos and video released by Russia's foreign ministry at the time showed the trolley, laden with brightly colored bags and suitcases, being pushed across a wintry landscape.