(CNN) It's a rare deal at a time when daily sparring over immigration is a worldwide reality.

Five Central American countries and Mexico inked an agreement last week that will help thousands of stranded Cuban immigrants make their way to the United States.

The group of Cubans, about 8,000 at the latest estimate, had been stuck in Costa Rica for weeks after Nicaragua closed its borders to them.

Now a group of Central American countries say the Cubans will be flown to El Salvador, then transported on buses to Mexico. Then they'll have a chance to cross into the United States.

Officials have said they'll start transporting the group of Cubans on flights this month. The first group of 180 will leave on a flight to El Salvador on Tuesday as part of a pilot program, Costa Rica's foreign minister said Wednesday. It won't be a free ride; the immigrants will have to pay about $550 to cover travel and visa costs, officials said.

Here's a look at some key questions in light of the deal:

Why are so many Cubans trying to get to the U.S.?

The idea of 8,000 new immigrants showing up at America's doorstep sounds like a large number. But experts say it's in keeping with a trend they've observed.

More than 43,000 Cubans entered the United States at ports of entry in the 2015 fiscal year, according to a recent Pew Research Center report , which cited U.S. Customs and Border Protection data. That represents a 78% increase over the previous year, according to Pew.

Several factors are fueling the trend, said Marc Rosenblum, deputy director of the U.S. immigration policy program at the Migration Policy Institute

Some fear the immigration policies that have welcomed Cubans into the United States could change now that relations between the countries are warming, Rosenblum said.

"There is this concern that Cuba special privileges will be eliminated, so Cubans are trying to get out while the getting's good," he said.

Don't most Cubans immigrate to the U.S. in boats?

Not anymore. While the U.S. Coast Guard said last year it was seeing an increase in the number of Cubans trying to reach the United States in rafts, even more are taking a different route.

"Over the last several years, we've seen pretty sharp increases in the number of Cubans, especially traveling by land," Rosenblum said.

Until recently, many flew into Ecuador, which didn't require a visa for Cubans until several months ago. From there, they trekked through Latin America until they reached the United States.

Will U.S. officials roll out the red carpet for this group when they arrive, or send them packing?

If recent history is any indication, the Cuban immigrants will be welcomed once they set foot on American soil.

The Cuban Adjustment Act of 1966 grants special privileges to Cubans, clearing some of the hurdles people from other countries face when immigrating.

"Even if they arrive illegally, they are admitted into the United States, and after a year and a day they are granted a green card," Rosenblum said. "They are the only country in the world that enjoys that privilege."

Immigrants from other countries have to go through screening processes as they make their asylum cases, but Cubans "are assumed to be refugees ... fleeing political persecution," Rosenblum said.

With immigration policies in the spotlight and changing U.S.-Cuba relations, could the policy change?

At this point, that's anybody's guess.

The latest U.S. government statement on the matter , released in December after a round of migration talks, said that "the administration has no plans to alter current migration policy regarding Cuba."

And on Wednesday, a Department of Homeland Security spokeswoman said, "There has been no administration change in Cuban policies."

When the Cuban Adjustment Act was passed, the U.S. government wanted to support Cuban dissidents and saw the Cuban government as a "uniquely authoritative, repressive regime," Rosenblum said.

These days, he said, that's "an increasingly difficult position to take."

"When you look around the world and you look around the hemisphere, there's a lot of other countries where people are fleeing at least as difficult circumstance, but aren't subject to similar privileges," Rosenblum said.

With political campaigning at fever pitch as the 2016 presidential election looms, it's unlikely there will be any overhaul of U.S. immigration laws. But the policies for the way Cuban immigrants are treated could shift in some ways, Rosenblum said, with increased screening or other limitations.

The Cubans on the way to the United States say they're focused on the present. Rafael Angel Suarez told CNN affiliate Teletica that he was full of emotion after learning of the deal the Central American countries struck.

"We were crying with happiness," he said.