President Barack Obama, in turn, hailed the pontiff as a moral force who is "shaking us out of our complacency" with reminders to care for the poor and the planet.
The White House mustered all the pageantry it had to offer as the pope arrived before an adoring crowd of thousands and a nation that seemingly cannot get enough of the humble pontiff who is rejuvenating American Catholicism while giving heartburn to some of its conservatives.
Speaking in a soft voice and halting English at the White House, Francis delivered a firm message against those who doubt the science of climate change, saying that the warming planet "demands on our part a serious and responsible recognition" of what awaits today's children.
It was a message sure to please the Obama White House, and liberals in general. But the pope had something for conservatives, too, with a pointed call to protect religious liberties "one of America's most precious possessions."