US presidential candidate Bernie Sanders, addressing a Vatican conference on social justice, has decried the "immoral" gap between the world's haves and have nots, saying it was worse today than more than a century ago.
Sanders noted that the Roman Catholic Church's first encyclical on social justice, written in 1891 by Pope Leo XIII, lamented the enormous gap between the rich and the poor.
"And let us be clear. That situation is worse today. In the year 2016, the top 1 per cent of the people on this planet own more wealth than the bottom 99 per cent," the Democratic contender said on Friday (local time).
"At a time when so few have so much, and so many have so little, we must reject the foundations of this contemporary economy as immoral and unsustainable," he said.
He also decried a system in the United States where "billionaires can buy elections".