It's well known that Pope Francis and President Donald Trump don't exactly see eye-to-eye on global climate change.

The pope recognizes the issue as a moral and religious challenge that must be addressed in order to make progress in alleviating poverty and other global goals.

And Trump, well, he doesn't think global warming exists in the first place.

In other words, there is a chasm between them on this issue. If anything, the differences sharpened in the days leading up to Trump's visit to the Vatican on Wednesday, with Trump still dithering on whether to keep the U.S. within the Paris Climate Agreement, which Francis supports.

In addition, Trump proposed a budget on Tuesday that would decimate climate science research across the federal government, making it harder for scientists to keep tabs on the changing planet.

It's against this backdrop that Pope Francis handed Trump a copy of his 2015 climate change letter, "Laudato Si: On the Care of the Common Home."

This was as awkward as it looks. Image: Pool/AGF/REX/Shutterstock

Francis also gave Trump copies of his other official writings, and signed a message of peace that he had issued. "Well I'll be reading them," the president said, according to a White House pool report.

Secretary of State Rex Tillerson, who spoke to reporters aboard Air Force One as it flew from Rome to Brussels, said it's unclear if climate change came up during Trump's audience with the pope.

However, it did come up in a meeting between Trump and the Vatican's Secretary of State, Cardinal Pietro Parolin.

“I don’t know in the meeting with the pope, but it did come up with Cardinal Parolin," Tillerson said. "We did have a good exchange on the climate change issue.”

“The cardinal was expressing their view that they think it's an important issue. I think they were encouraging continued participation in the Paris accord," Tillerson said.

"But we had a good exchange [about] the difficulty of balancing addressing climate change, responses to climate change, and ensuring that you still have a thriving economy and you can still offer people jobs so they can feed their families and have a prosperous economy. And that’s a difficult balancing act to take, and so I think we had a good exchange there, and we look forward to having further talks with them on climate policy.”