Swedish staff have left the country's embassy in North Korea but the diplomatic mission in Pyongyang remains open and is being staffed by local employees, officials said Tuesday.

"The main reason is that we have temporarily relocated our diplomats who are either on holiday or are part of a (scheduled) rotation," Foreign Ministry spokesman Anton Dahlquist said. "Let me stress that we maintain our diplomatic relations with North Korea."

But Dahlquist added that "the situation (in North Korea) for the diplomats and the international organizations has increasingly become more difficult recently, including traveling, receiving diplomatic mail and the like. This is partly due to the COVID-19 pandemic."

North Korea has imposed a lockdown and shut its border with China, its main ally and economic lifeline, in response to the coronavirus.

Sweden has had diplomatic relations with North Korea since 1973 and is one of the few Western countries with an embassy in Pyongyang. It provides consular services for the US in North Korea. (AP)