'North Korea world's worst' for slavery

North Korean leader Kim Jong Un speaks during a visit to a machine factory in North Hamgyong Province. Photo / AP

North Korea has the largest number of slaves in the world, with just over one in 10 of the population - about 2.6 million people - subjected to forced labour.

The shocking abuse, which includes young children being coerced into exhausting manual work, was outlined yesterday by the 2018 Global Slavery Index, the largest survey in the world of human slavery and forced marriage.

It also found that more than 400,000 people could be living in "modern slavery" in the United States, a condition of servitude broadly defined as forced and state-imposed labour, sexual servitude and forced marriage.

"The United States is one of the most advanced countries in the world yet has more than 400,000 modern slaves working under forced labour conditions," said Andrew Forrest, founder of the organisation behind the report, the Walk Free Foundation, which campaigns to end slavery.

Based on 71,000 individual interviews in 48 countries, the report concludes that an estimated 40.3 million men, women and children worldwide are being forced to work against their will.

About 2.6 million of them toil unseen behind the closed borders of the repressive and secretive regime in North Korea. Such is the extent of their mistreatment that the foundation dedicated a spin-off report specifically to shine a spotlight on their plight.

Of 50 defectors interviewed over the course of a year, all but one described servitude either as children or adults, or in some cases both.

Their accounts dated from 2011 to 2016.

Child labour, through communal activities called "mobilisations", is an integral part of North Korean society.

Pupils, even of primary school age, are required to strive for up to two months at a time in back-breaking farm work or manual labour, such as collecting discarded coal beside rail tracks. Their schools, and not the children, receive payment for the work and any students refusing to participate risk punishment or even expulsion.