The number of people attempting to cross the U.S.-Mexico border from countries beyond Mexico and Central America's Northern Triangle — including residents of Haiti, Cuba, Romania and India — has spiked during recent months.

Why it matters: On top of natural disaster and economic crises in home countries, the growing backlog of asylum cases in the U.S. — which often allows migrants to live and work in the country as their case plays out in court — is being conveyed to friends and relatives. It can prompt them to catch flights to Central America.

• When border enforcement resources are overwhelmed, some smugglers and migrants also see it as an opportune time to cross — regardless of their clients’ origin, Jessica Bolter of the Migration Policy Institute told Axios.
• Experts say it could be a sign of a more permanent shift in U.S. border migration.
• “The Biden administration has made it clear that our borders are not open and individuals and families are subject to border restrictions, including expulsion," a Department of Homeland Security spokesperson said.

By the numbers: Last month, the Border Patrol encountered more than 33,000 people crossing into the U.S. from nations other than Mexico, Guatemala, Honduras and El Salvador, according to Department of Homeland Security data.

• That's up from about 9,000 in January.
• It's also an increase of 35% from March — even as numbers from the Northern Triangle fell slightly during that time period. It's also 2.5 times the number who crossed in June 2019, which was the highest month of the previous three fiscal years.
• 30% of all family members who crossed the border in April came from these less-typical countries of origin.

Between the lines: Most are adults or families, rather than unaccompanied minors. They often fly into Central American countries before traveling through Mexico to the border, multiple experts said.

• Border agents have encountered migrants from more than 160 countries in recent months, the New York Times reported, with notable spikes in Ecuadorians, Brazilians and Venezuelans.
• Rep. Jason Smith (R-Mo.) told Axios that when he visited the border with other Republican colleagues this month, they witnessed a family of five Romanians surrendering to Border Patrol in Yuma, Arizona.
• A Reuters photographer has reportedly witnessed nearly 200 Romanians crossing the border into Texas.
• Border Patrol agents have encountered an unaccompanied 1-year-old from Ecuador, two teenagers from Bangladesh, a 14-year-old from India and a 17-year-old from Armenia during recent days, according to government data provided to Axios.

The big picture: The makeup of the migrant population at the border shifted in the early 2010s, from predominantly Mexican adults to large numbers of families and children from Central America.

• The U.S. immigration system is still struggling to adjust to that shift, let alone the addition of distant migrants.
• "Immigration from Central America is important," Cris Ramón, an independent research consultant and migration analyst told Axios, "but we can no longer assume that that's going to be the only source of immigrants coming to the U.S.-Mexico border, because of the fact that immigrants are far more mobile, with being able to fly to countries like Mexico."

Flashback: The Customs and Border Protection agency confirmed to Congress in March that four people arrested at the border since Oct. 1 match names on the FBI's Terrorist Screening Database.

• Three were from Yemen and one was from Serbia.