WASHINGTON (AFP) - White House presidential candidate Bernie Sanders said many of his primary losses to fellow Democrat Hillary Clinton took place because "poor people don't vote," in interview excerpts released Saturday (April 23).

Sanders has centered much of his presidential campaign on fighting income inequality, but he lost to Clinton in 16 of 17 US states with the biggest pay gaps.

When asked during an interview with NBC television's "Meet the Press" program about why he lost in such places, he quipped: "Well, because poor people don't vote." "I mean, that's just a fact. That's a sad reality of American society." But Sanders insisted that "we have to transform" that trend.

Excerpts of the interview were provided on Saturday, a day before they were due to air.

Sanders noted that he had succeeded in getting many young voters on board, but has had a harder time getting his message across to lower income earners.

He claimed that "80 per cent of poor people did not vote" in 2014 elections.

US Census data on those elections found that just 24.5 per cent of US citizens aged 18 and over who earned less than $10,000 a year cast ballots, meaning that presumably 75.5 per cent did not.

"We have... one of the lowest voter turnouts of any major country on Earth," Sanders remarked.

A Pew study last year found that US voter turnout lags behind most developed countries, though ahead of Japan, Chile and Switzerland.

"If we can significantly increase voter turnout so that low-income people and working people and young people participated in the political process, if we got a voter turnout of 75 per cent, this country would be radically transformed," Sanders said.