Democratic presidential candidate Bernie Sanders said in an interview with The Associated Press that he met with Pope Francis.

Sanders said the meeting took place Saturday morning before the pope left for his one-day visit to Greece. He said he was honored by the meeting, and that he told the pope he appreciated the message that he is sending the world about the need to inject morality and justice into the world economy. Sanders said it's a message he has been sending as well.

"We had an opportunity to meet with him this morning," Sanders said. "It was a real honor for me, for my wife and I to spend some time with him. I think he is one of the extraordinary figures not only in the world today but in modern world history."

Sanders said it was a brief meeting at the papal residence. "I told him that I was incredibly appreciative of the incredible role that he is playing in this planet in discussing issues about the need for an economy based on morality, not greed."

Sanders and wife stayed overnight at the pope's residence, the Domus Santa Marta hotel in the Vatican gardens, on the same floor as the pope.

They were seen at the hotel reception, carrying their own bags.

Dr. Jeffrey Sachs, a Sanders foreign policy adviser and adviser to the United Nations on climate change, said there were no photographs taken of the meeting.

Sachs said Sanders and his wife Jane met the pope in the foyer of the domus as the pope was leaving for Greece. The meeting lasted for about five minutes, Sachs said.

Sanders traveled to Rome to attend a Vatican conference on economic inequality and climate change. He is an admirer of the pope and has praised the pope's views on poverty and the environment.

The Vermont senator is challenging Hillary Clinton for the Democratic nomination.