Pope Francis met with U.S. Senator Bernie Sanders in the Vatican on Saturday morning and the two discussed the need for morality in the world economy.

Columbia University Professor Jeffrey Sachs said that the meeting took place in Domus Santa Marta, the pope’s residence, where Sanders had slept Friday night after addressing a Vatican conference on social justice.

Sachs, who has advised the United Nations on climate change, said Sanders thanked the pope for his pronouncements on the need for morality in the global economy and statements in defense of the environment.

“The pope thanked the senator for coming to the meeting and for coming to speak about the moral economy,” Sachs said.

The meeting lasted about five minutes, said the economist Jeffrey D. Sachs, an adviser to the Sanders campaign who said he had been present.