UNHCR Goodwill Ambassador Ben Stiller stands with Syrian refugee Hanadi (21), and her children Hassan (4), Mayed (3) and Abed (2) at an informal settlement in northern Lebanon where the family has lived for the past three years, March 5, 2019. UNHCR/Michael Muller

United Nations -- As the Syria war enters its 9th year the fighting is easing, but for 5.6 million refugees who have fled the brutal conflict, the future is still unclear. Will they be able to go home? If they can't, where can they go?

Actor, director, comic and activist Ben Stiller, appointed a U.N. refugee agency (UNHCR) Goodwill Ambassador last year, visited Lebanon in early March to meet some of the refugees. In a wide-ranging interview at U.N. Headquarters, he told CBS News he met people "living in limbo," and urged the U.S. to take in more of the displaced and not think of them as "some sort of enemy."

The U.N.'s High Commissioner for Refugees (UNHCR), Filippo Grandi, has called the magnitude of the humanitarian crisis "staggering." The U.N. estimates that 2.6 million children have been forced to flee their homes but are still living inside Syria, and 2.5 million more youngsters are living as refugees outside the country.

Get Breaking News Delivered to Your Inbox

"The challenge is just to survive"

Stiller's mandate as a Goodwill Ambassador is to use his high profile to shine a light on the crisis and let the world know how to help.

In an informal refugee settlement in northern Lebanon, Stiller told CBS News he met Syrian mother Hanadi and her three children, Hassan, Mayed and Abed, who range in age from two to four years old. They fled their home in the northern Syrian city of Homs for safety in 2016.

"They are obviously struggling," Stiller said. Hanadi is raising her kids alone after her husband went back to Syria but then disappeared. "It's a very tough situation."

"A lot of these people, they don't know if it is safe to go back or not. They have to make that determination themselves. In the meantime, they are living in this limbo, in this case in Lebanon," he said.

Making matters worse, "there are restrictions on refugees actually working; most of it's against the law… The challenge is just to survive."

He's the youngest vegetable salesman in Lebanon. This young Syrian refugee showed @RedHourBen how he's helping to support his family. pic.twitter.com/ykit0K6gHQ — UNHCR, the UN Refugee Agency (@Refugees) March 12, 2019

In Lebanon's Bekaa Valley Stiller met another refugee family, including eight-year-old twins Yazan and Razan. Yazan sells vegetables from a cart at the side of the road. His parents fled shelling in Damascus, in the middle of the night, when he was just four months old.

"This is the sweetest, happiest kid," Stiller said. "That innocence is still there, and he is supporting his family."

"But how long can that last? The reality is that there are psychological implications with the trauma that will last for a long time… It's tough to see children in that situation, where you know that their innocence is going to go away."

Like the majority of the kids at the camp, Yazan isn't in school, Stiller said. They have to move often and winters in the Bekaa Valley are harsh. Before the war, Yazan's father was a taxi driver who provided for the family, but times became so dire he considered selling his kidney at one point.

"These stories are heart wrenching," the actor said. "And then you walk away, and it's hard to accept that those people right now are still living in those conditions as we are talking about it. What can you do about it? There's nothing you can do about it other than help change, and try to fix the problem."

Not safe to go home

Stiller said he tries to inject his trademark humor into the difficult situation.

"You know, the kids make you laugh because the kids just want to have fun and play," while he tries to, "find something in common with the parents, because we are all parents."

"Laughing is a human thing, and it is a great way to connect. I always walk away from these experiences having felt it is a very positive thing."

That is short-term relief, however, and while U.N. agencies including UNHCR and the World Food Program provide assistance, education, shelter, and social services, Stiller said "it's never enough."

"That is why I am talking about it. The reality is that these people are suffering through no fault of their own. These are innocent victims of war and conflict," the actor said, adding that, "countries like America and countries all over the world need to contribute" to efforts to get the millions of displaced Syrians either back to their homes, or settled into new ones.

All last year, 56,000 refugees returned to Syria -- only about 1 percent of the total number --and only 6 percent of the refugees surveyed by the United Nations in December said they would be willing to return in the coming 12 months. Most of them, 75 percent, said they hoped to return "one day."

But France's U.N. Ambassador Francois Delattre told CBS News "the conditions determined by the U.N. to allow for a safe, voluntary and dignified return of Syrian refugees are not met yet."

He said refugees have no security guarantees if they try to go home. They risk arbitrary detention, forced conscription and even torture. Even if they make it back, they could find their property has been confiscated by the Syrian regime.

So Stiller said it's important that other countries step up, open their doors, and not vilify the displaced.

"They are not to be feared. They are human beings just like you or I," he said. "We are a country that was built on refugees and immigrants. They should not to be demonized. They shouldn't be made to be seen as some sort of enemy."

"Refugees are additive to the society, they help us, they always contributed to the economy and they should be welcomed as we've always welcomed refugees into our country," the actor said. "I hope that our resettlement numbers come back up to what they have been in the past, because it's an important thing."