(NewsNation) — The majority of migrants crossing the U.S.-Mexico border are coming from impoverished countries in South America and the Caribbean Islands, driven by poverty and political instability.

As of Thursday, the U.S. will begin denying entry to Cubans, Haitians and Nicaraguans who cross the border from Mexico without authorization, President Joe Biden announced. His announcement expanded an existing effort to stop Venezuelans from entering the U.S.

U.S. Customs and Border Protection reported the following total encounters with migrants from those nations in 2022:

• Venezuela: 189,520
• Haiti: 53,901
• Nicaragua: 163, 876
• Cuba: 220,908

An October NewsNation/Decision Desk HQ survey found that 22.27% of voters believe violence and corruption are most responsible for increases in illegal immigration.

The number of Caribbean migrants entering the U.S. via the sea has risen to levels not seen since the 1990s after the Soviet Union dissolved, according to the Migration Policy Institute (MPI). They are finding success with a new route.

“That migration pattern has happened for a while where Cubans cross the Caribbean land in Mexico and come up through the southern border because of the interdictions by the Coast Guard, going straight to Miami,” said Kevin Appleby, the acting executive director of the Center for Migration Studies in New York.

Cubans began migrating to the U.S. in larger numbers decades ago, following Fidel Castro’s communist revolution, according to the MPI.  Then in 1966, Congress passed the Cuban Adjustment Act, allowing Cubans to become what is known as lawful permanent residents after they had been in the U.S. for at least a year. 

The Cuban population in the U.S. grew from 79,000 in 1960 to 439,000 in 1970 as a result, according to the Library of Congress.

More recently, the COVID-19 pandemic and U.S. sanctions against Cuba took a hit on the nation’s economy, exacerbating poverty and pushing more people to the U.S., the New York Times reported.

In nearby Haiti, a 30-year dictatorship and its collapse as well as endemic poverty and destructive natural disasters have been some of the main driving factors behind Haitian natives’ move to the U.S, the institute reported.

“Haiti is a failed country politically,” Appleby said. “It’s got political instability and it’s the poorest country…at least in this hemisphere.”

The stream of Haitians migrating to the U.S. jumped in the last decade after an earthquake rocked the island nation in 2010, according to census data analyzed by the MPI.

In Venezuela, economic collapse, political upset and a humanitarian crisis have driven the country’s natives to flee, according to the International Organization for Migration.

The International Monetary Fund reported that the region’s migration can largely be attributed the nation’s economic downturn. As a result, Venezuelans were subjected to harsh living conditions and many struggled to meet basic needs, driving them out of the country.

“The COVID-19 pandemic compounded the country’s economic and humanitarian crisis, and in 2020 more than 95% of Venezuelans were living below the poverty line,” the IMF reported.

The number of Nicaraguan migrants heading to the U.S. also has risen over the past year and a half, according to the Council on Hemispheric Affairs.

Manuel Orozco is a senior fellow and the director of the Migration, Remittances and Development Program at the Inter-American Dialogue, a U.S.-based policy think tank. In an opinion piece for NewsNation’s partner The Hill, he noted that Nicaraguan businesses have been “extorted by mafia-like police officers, Catholic leaders are persecuted for supporting democracy, residents (even Americans) are detained and sentenced for decades.”

“… those who can afford it, vote with their feet and migrate,” Orozco wrote.