AMNA NAWAZ: Syrian President Ahmed al-Sharaa met with President Trump today, the first White House visit by a Syrian leader since the country became independent nearly 80 years ago.

GEOFF BENNETT: And, as Nick Schifrin reports, today, Damascus joined the global alliance countering ISIS, and the Trump administration extended temporary sanctions relief.

NICK SCHIFRIN: Today in the Oval Office, a once unthinkable partnership, Ahmed al-Sharaa, former prisoner of U.S.

forces, welcomed to the seat of us power.

His path from warrior to the West Wing praised again today by President Trump.

DONALD TRUMP, President of the United States: We want to see Syria become a country that's very successful, and I think this leader can do it.

I really do.

I think this leader can do it.

And people said he's had a rough past.

We have all had rough pasts.

NICK SCHIFRIN: Just one year ago, Abu Mohammad al-Julani led Hay'at Tahrir al-Sham, a U.S.-designated terrorist group, with a $10 million bounty on his head.

From 2005 to 2011, he was detained by U.S.

forces as an insurgent in Iraq.

But, last December, HTS toppled Syria's half-century of tyranny, ending 14 years of bloody civil war and beginning al-Sharaa's transformation from jihadi soldier to statesman to sportsman of sorts.

With the U.S.'

top Middle East officer in the background, this weekend, al-Sharaa shot hoops with the men who, a few years ago, would have been responsible for his arrest.

MOUAZ MOUSTAFA, Executive Director, Syrian Emergency Task Force: It's historic in its own right, right?

This is the first Syrian president to ever enter an American White House.

NICK SCHIFRIN: Mouaz Moustafa leads the Syrian Emergency Task Force that advocates for Syrian democracy and met al-Sharaa as recently as this weekend.

MOUAZ MOUSTAFA: Syria itself, which was under the influence of China, Iran, North Korea, Russia, is now coming and wanting to be an ally of Western democracies and the first Syrian president ever visits the White House ever.

That, I think, is the big story.

NICK SCHIFRIN: Today, Syria announced it would become the 90th partner in the Global coalition against ISIS.

Already, U.S.

troops train with Syrian forces to try and ensure Syria can help prevent an ISIS resurgence.

And a U.S.

official tells "PBS News Hour" the U.S.

has -- quote -- "advised, assisted, and enabled" 22 operations against ISIS over the past month with Syrian forces.

This weekend, Syria's Interior Ministry announced a massive raid targeting ISIS militants, and Syria enables U.S.

airstrikes.

This year, the U.S.

military has targeted an ISIS or al-Qaida leader in Syria at least eight times.

MOUAZ MOUSTAFA: These joint counterterror, counter-ISIS, sometimes counter-al-Qaida operations are ongoing and have been successful.

But they have been going on kind of under the table in a way.

Today, both the U.S.

military and the Syrians will have the tools, the ability to publicly and privately work and coordinate on counterterror operations.

NICK SCHIFRIN: But what is not being announced today, the repeal of punishing sanctions on Syria known as the Caesar Act imposed against Bashar al-Assad for waging a war of brutality and torture against his own people.

Today, the administration extended its suspension of the Caesar Act implementation for another 180 days.

And a senior administration official tells "PBS News Hour": "The Trump administration supports the full repeal of the Caesar Act.

Removal is key to allow U.S.

business and regional states to operate in Syria."

But only Congress can do that.

And Republican Senator Lindsey Graham has resisted.

SEN.

LINDSEY GRAHAM (R-SC): But Syria has much to prove to me in the region before that can happen.

MOUAZ MOUSTAFA: Millions of Syrian refugees want to go home, and they can't rebuild as long as Caesar is even a shadow of being snapback sanctions or existing as an authority.

And if Caesar remains, it is shattering to the Syrian economy, despite all the other things.

And we don't want to see a failed state in Syria.

That's bad for the whole world.

NICK SCHIFRIN: Also not announced today, a de-escalation agreement with Israel, whose soldiers continue to occupy strategically important land in Southern Syria after a series of airstrikes on Syrian military and government targets.

MOUAZ MOUSTAFA: The goal here is to, if anything, stop the bombardment and the incursions that have happened by the Israelis.

And he also did say that this would open the door for a permanent peace with Israel in the long term.

NICK SCHIFRIN: There is also no peace yet inside parts of Syria.

Bedouins in the south accuse the government of committing violence and making sectarian clashes worse.

Syria's Christians blame the government for failing to protect them.

Kurds in the north are worried about government pressure.

And former ruling Shiite Alawites accused government forces of a sectarian massacre.

DR.

MORHAF IBRAHIM, President, Alawites Association of the United States: The only actually reason these guys, these people were killed because of the fact that they were Alawites.

NICK SCHIFRIN: Dr.

Morhaf Ibrahim is the president of the Alawites Association of the United States.

DR.

MORHAF IBRAHIM: It's just an al-Qaida mentality and Islamic Jihadist mentality as well, that if you believe in different God or if you practice your faith in different ways, you have to be killed.

And this is the background of Ahmed al-Sharaa and his government, and this is why U.S.

government should be careful in dealing with this guy.

NICK SCHIFRIN: But today, outside the White House, al-Sharaa received a hero's welcome.

They celebrated a man who's come a long way, even if others say he's got a long way to go.

For the "PBS News Hour," I'm Nick Schifrin.