VATICAN CITY (AP) — When Pope Francis meets with President Donald Trump at the Vatican May 24, the world will be watching how the Argentine "slum pope" interacts with the brash, New York billionaire-turned-president.

On many issues, the two men couldn't be more different. Francis wants bridges between nations, not the walls Trump is building. Francis wants an end to the use of fossil fuels, while Trump has pledged to cancel payments to U.N. climate change programs and pull out of the Paris climate accord. U.S. bishops have praised the Trump administration for its abortion stance, but oppose Republican health care reform plans because of the impact on the poor.

Despite the obvious differences, Trump and Francis share a populist appeal and speak with a down-to-earth simplicity that has endeared them to their bases.