The United Nations monitor on extreme poverty and human rights has embarked on a coast-to-coast tour of the US to hold the world’s richest nation – and its president – to account for the hardships endured by America’s most vulnerable citizens.

The tour, which kicked off on Friday morning, will make stops in four states as well as Washington DC and the US territory of Puerto Rico. It will focus on several of the social and economic barriers that render the American dream merely a pipe dream to millions – from homelessness in California to racial discrimination in the Deep South, cumulative neglect in Puerto Rico and the decline of industrial jobs in West Virginia.

With 41 million Americans officially in poverty according to the US Census Bureau (other estimates put that figure much higher), one aim of the UN mission will be to demonstrate that no country, however wealthy, is immune from human suffering induced by growing inequality. Nor is any nation, however powerful, beyond the reach of human rights law – a message that the US government and Donald Trump might find hard to stomach given their tendency to regard internal affairs as sacrosanct.

The UN poverty tour falls at a singularly tense moment for the US. In its 2016 state of the nation review, the Stanford Center on Poverty and Inequality placed the US rank at the bottom of the league table of 10 well-off countries, in terms of the extent of its income and wealth inequality.

It also found that the US hit rock bottom in terms of the safety net it offers struggling families, and is one of the worst offenders in terms of the ability of low-income families to lift themselves out of poverty – a stark contrast to the much-vaunted myth of the American dream.

The US poses an especially challenging subject for the UN special rapporteur because unlike all other industrialized nations, it fails to recognize fundamental social and economic rights such as the right to healthcare, a roof over your head or food to keep hunger at bay. The federal government has consistently refused to sign up to the international covenant on economic, social and cultural rights – arguing that these matters are best left to individual states.