Happening now, the first American Pope, Pope Leo the 14th,

takes the helm of the Catholic Church and celebrates his first mass as pontiff,

as he encourages the world's 1.4 billion Catholics to go beyond a superficial faith.

Trade war, thaw. President Trump is now floating an 80% tariff on China but says he'll leave the negotiations

up to his Treasury Secretary. U.S. and Chinese officials are set to meet tomorrow in Switzerland

as both nations signal that the status quo is unsustainable. Welcome to our viewers here

in the United States and around the world. I'm Wolf Blitzer with Pamela Brown and you're in the Situation Room.

Happening now, the world is getting to know the first American Pope as he takes the helm of the Catholic Church. This morning Leo the 14th celebrated his first Mass since being chosen as

Pontiff, starting off with another first addressing the Cardinals at the start of his

homily in English. Through the ministry of Peter, you have called me to carry that cross and to be blessed with that mission.

And I know I can rely on each and every one of you to walk with me.

As Pope, he will face a host of hot button issues, including immigration.

His older brother says the pontiff thinks the U.S. is going about it all wrong.

I think he sees the United States is headed in the wrong direction in terms of immigration.

That this is a total injustice.

These are people.

It doesn't matter where they're born. These are people.

Doesn't matter where they're born. They are people first.

And so they need to be treated.

Our Ben Wiedeman has been in St. Peter Square this week,

and he's joining us now live, Ben.

How was the new Pope's message received?

...