WASHINGTON (AFP) - United States President Barack Obama on Wednesday spoke approvingly of an "eloquent" argument by Pope Francis on rising inequality in societies split between the very poor and the super rich.

Mr Obama referred to the Pontiff's remarks in his first Apostolic Exhortation as part of the president's own prolonged meditation on poverty in a speech on inequality and politics in America.

"Some of you may have seen just last week, the pope himself spoke about this at eloquent length," Mr Obama said in a speech to the Centre for American Progress think-tank in Washington.

"How could it be, he wrote, that it's not a news item when an elderly homeless person dies of exposure, but it is news when the stock market loses two points?" Pope Francis argued in the exhortation, published this month, that such conflicted values marked a "case of exclusion" in an unequal society and wrote that "masses of people find themselves excluded and marginalised: without work, without possibilities, without any means of escape".

It was not the first time that Mr Obama had praised Pope Francis, who was elected in March and has caused a stir with his austere style and pronouncements on poverty.

In October, the president told CNBC that he was "hugely impressed" with the pope's humility and empathy to the poor.