Covid has dealt North Korea’s secretive dictatorship its biggest economic blow since the 1990s famine that killed hundreds of thousand of people, according to new figures.

Monitoring the totalitarian regime is a difficult task for economists but South Korea’s central bank estimates that the virus, combined with natural disasters and international sanctions, wiped 4.5pc off its economy in 2020 - the worst drop since 1997.

The latest fall took the size of the North Korean economy to its smallest since supreme leader Kim Jong-un took over in 2011. Output for the entire economy last year fell to 31.4m trillion won, or £19.6bn according to the Bank of Korea - less than 1pc of the size of Britain's economy.

Kim, who wept openly as he apologised for his leadership failings last October, also warned of a new “arduous march” for North Koreans earlier this year. Analysts took his comments as a warning of fresh food shortages.

But his decision to shut borders more than a year ago due to Covid has caused trade to plunge with its main partner China.

The dictatorship’s exports dropped by two-thirds to just $90m (£64m) in 2020, while imports plunged 74pc, according to the Bank of Korea report.

The economic slump is the sharpest since 1997, when a series of droughts, floods and botched economic policies caused a famine that killed an estimated 240,000 to 3.5m people.

Kim warned last month that the “food situation is now getting tense”, but foreign aid organisations have had trouble getting into North Korea to deliver humanitarian assistance. The World Food Program said last year it was critical for the country to ease restrictions on the entry of international personnel.

Despite North Korea’s economic struggles, Kim has shown no willingness to begin discussions on cutting his nuclear arsenal in return for economic aid from other countries including the US since the diplomatic coup of his meeting with then president Donald Trump.

Relations between Kim and South Korean President Moon Jae-in showed signs of thawing this week as they agreed to restore hotlines cut for more than a year due to political tension, improving the dim prospects for a breakthrough in an extended stalemate in nuclear talks.