Brazil is tightening entry requirements from Monday after a surge in migrants disembarking during stopovers at Sao Paulo's main airport in a bid to seek asylum in the country.
Their goal is to enter Brazil and make their way overland to the United States.
"Brazil has become a route for criminal organizations that smuggle immigrants and traffic people. Authorities have identified an exponential increase in the number of nationals mainly from Asian countries," Brazil's justice ministry said in a statement to AFP.
The travelers buy plane tickets with final destinations in other South American countries, and are advised by people smugglers to apply for asylum in Brazil.
However, the statement said, these travelers are actually seeking to head north through Colombia and then Panama via the perilous Darien Gap jungle in the hope of a better life in the United States.
Most arrive at Brazil's biggest aviation hub, Sao Paulo's Guarulhos International Airport, where hundreds of migrants can spend weeks waiting in a crowded transit zone.
Last week authorities estimated 481 people were currently stuck in limbo in the airport. Local media report that many are from India, Nepal and Vietnam.
A local television station showed images last week of dozens of people wearing masks in a long line waiting for food.
On August 13, a Ghanaian man died five days after his arrival, after falling ill and being transferred to a public hospital, where he suffered a heart attack, the Federal Police told AFP.
Transit visa required
To clamp down on the trend, Brazil's government decided that from Monday, travelers from countries for which Brazil requires a visa will now have to obtain a transit visa for a stopover.
The new rules also require asylum seekers to prove that they are suffering political persecution or violence in their countries of origin.
Guarulhos Airport is one of the busiest in Latin America, welcoming some 35 million travelers annually.
According to official data, the number of asylum applications at the airport has increased 60-fold in ten years, from 69 in 2013 to 4,239 in 2023.
This year there have already been 5,428 applications filed from January to July, an average of 25 per day.
Numbers surged further in August with 41 asylum applications per day.
A recent report by Brazil's Public Defense, an independent organization that offers legal aid to the poor, highlighted "repeated situations of human rights violations", particularly for children, unaccompanied teens or women "in situations of extreme vulnerability".
Migrants "sleep on the ground" and "the demand for medical care is only increasing", the report said, also reporting "very poor hygiene and food conditions".
Following an emergency meeting called last week by the prosecutor's office, authorities have increased the number of staff processing asylum applications to reduce delays.