"I was very moved by the invitation, which just was made public today," the senator told MSNBC's "Morning Joe" on Friday.
"Obviously there are areas where we disagree on," Sanders said, pointing to "women's rights" and "gay rights."
"But he has played an unbelievable role -- an unbelievable role -- of injecting the moral consequence into the economy.
"You know, people think Bernie Sanders is radical? Uh-unh. Read what the pope is writing.
he is saying is not only that we have to pay
attention to what he calls the dispossed;
and again, we don't talk about it enough.
These are the children who have no jobs all
over the world; youth unemployment is off
the charts. The elderly people who are
watching this program now who are trying to
get by on $11,000 a year -- we don't talk
"But you know what else he's even doing? He's talking about the idolatry of money; the worship of money; the greed that's out there. How our whole culture is based on, I need more and more and more. And I don't have to worry about veterans sleeping out on the street or elderly people who can't afford their presciption drugs.
"And he's trying to inject a sense of morality into how we do economics...and we need that absolutely, desperately."
The Vatican conference on April 15 will address social, economic and environmental issues.
"Pope Francis has made clear that we must overcome the globalization of indifference in order to reduce economic inequalities, stop financial corruption and protect the natural environment. That is our challenge in the United States and in the world,” Sanders said in a statement carried by wire services.
The Washington Post quoted Sanders as saying, “I am grateful to the Vatican for inviting me to talk about an issue that is very dear to my heart, which is how we create a moral economy that works for all of the people rather than just the top one percent."
Sanders said he also plans to address "the planetary crisis of climate change and the moral imperative to make sure we leave this planet in a way that is healthy and habitable for future generations.”