White House acting chief of staff Mick Mulvaney said on Tuesday a little known fact about President Trump is that he often brings up Christianity when meeting with foreign leaders.

“What you don’t know about is what goes on behind closed doors. I very rarely talk about my private meetings with the president,” Mulvaney said at the National Catholic Prayer Breakfast in Washington, D.C. “I can assure you that I have been sitting with him in the Oval Office, in the Cabinet Room, with leaders from around the world where he will look at them and say, ‘Now, you’re not doing enough to take care of the Christians in your country,’ or, ‘Thank you for helping the Christians in your country.’”

“That is heavy stuff, and it strikes me it’s probably something that hasn’t been articulated in the Oval Office in way too long,” he added.

[ Read more: Pete Buttigieg questions Trump's faith in God]

Addressing a crowd of more than 1,000 Catholics, Mulvaney said the Trump has embraced faith in the White House and encourages Christians and people from all religions who work there to “take their faith and work it into our policies.”

“If you take a look at what the administration has done in the first two and a half years, I think you can see the principles of our faith being manifested,” Mulvaney said.

Mulvaney told attendees that too few people across the country are showing their faith and publicly embracing it. “Not enough people are open in their faith, not enough people are comfortable saying, ‘Yeah, you know what? I went to church today,’” Mulvaney said.

Mulvaney also said the Trump administration stands firmly behind the anti-abortion movement in the U.S. Mulvaney recounted an anecdote from this year’s State of the Union address, saying that just before Trump’s address he was seen adding written notes into the final copy. Those notes turned out to be additional language speaking out against abortion and condemning controversial comments Virginia Gov. Ralph Northam made about late-term abortions around that time.

The National Catholic Prayer Breakfast has been held for 15 years. Past speakers have included Vice President Mike Pence, former President George W. Bush, and the late Supreme Court Justice Antonin Scalia.