More than half of them face challenges accessing food, housing, and stable employment, the UN says.

But despite the difficulties facing them abroad, the flow of Venezuelans escaping turmoil in their homeland has not let up.

Aid agencies warn that these migrants risk being forgotten amid other crises.

"There's no question both that it is a major protracted crisis that is shaking the region [of Latin America]," David Miliband, president of the International Rescue Committee, told the BBC.

"But it is also clear that the competing priorities for global attention - Ukraine, famine in East Africa, trauma in Afghanistan - are draining attention in a way that is quite dangerous."

More than 80% of those who have left Venezuela are living in Latin America and the Caribbean, in countries which often already struggle to provide health and education to their own nationals.

Venezuela's population has fallen from 30.08m in 2015 to an estimated 28.25m now based on latest UN figures.

"Many of the governments in Latin America are trying to do the right thing in managing the movement of Venezuelans, but it's a big challenge," Mr Miliband said on a visit to Colombia, which is hosting 2.48m Venezuelans.

"It's dangerous to presume that this burden can just be borne indefinitely," he warned.

Other aid agencies have also been sounding the alarm. The UN's Special Representative for Refugees and Migrants from Venezuela, Eduardo Stein, has said that half of all Venezuelan refugees and migrants cannot afford three meals a day and lack access to safe and dignified housing.

It is an experience 33-year old Sarahí recalls only too well. "For more than a year, I had to make a choice between paying for a roof over my head or paying for food," she recalls.

The investigative journalist - who covered human rights and freedom of speech - left Venezuela 10 years ago after receiving threats. She is withholding her surname for safety reasons.

Sarahí settled in neighbouring Colombia and is now helping integrate Venezuelan migrants who have followed in her footsteps.

She says that while Venezuelans' reasons for leaving are manifold - ranging from seeking access to health care and education, which have collapsed in many parts of Venezuela, to searching for employment - many face the same difficulties once they arrive.

"Many of us, even if we have university degrees, have to work in whatever we can to survive and to support our families who're still in Venezuela," she explains.

"I came on my own, with just one suitcase. It contained clothes for the colder climate in Bogotá, my university certificates and photos of my family."

While most Venezuelans have headed to Colombia, Peru and Ecuador, a growing number are embarking on an even more dangerous trek: north across the jungle expanse known as the Darién Gap to Panama and beyond.

More than 3,000 migrants, most of them Venezuelans, are making the crossing each day, figures from the Colombian authorities suggest.

The 97km-trek (60 miles) across swamps and mountains can take more than a week to complete and robberies and rapes are not uncommon in the lawless jungle expanse.

One of those who has made it is Gabriel Moreno. The Venezuelan told the International Red Cross in Panama that it took him two and a half days to walk across the Darién Gap with his wife.

He says that it was thanks to his physical fitness he managed to complete the crossing faster than most.

And while many Venezuelans will have already walked hundreds or even thousands of kilometres before they even reach the Darién jungle, Mr Moreno's stamina stems from having crossed seven countries.

"My journey started in 2016 when I decided to leave Venezuela for Peru," he says. "My ambition was to build a home for me and my family somewhere where we could live in peace and wouldn't be oppressed."

From Peru, Mr Moreno travelled south to Chile and on to Argentina before heading north again through Bolivia, Chile, Peru, Ecuador and Colombia to Panama.

Like many Venezuelan migrants, he made most of the journey on foot. "I've had to walk a lot," he says, before adding that he will now try to stay in Panama.

Mr Moreno's epic journey reflects a phenomenon aid agencies have increasingly witnessed as the Covid pandemic hit Latin American countries hard.

With the opportunities in the informal economy - which is where many migrants first work - severely curtailed during lockdowns, Venezuelans who had settled in a host nation saw their meagre incomes dwindle and had to move again and again.

This phenomenon also throws up challenges for the host countries, says Natalia Durán. She has co-ordinated the response to the migration in the Colombian city of Bucaramanga, which has received more than 40,000 Venezuelans in recent years.

"You have a wide variety of people in different situations, ranging from those looking to settle permanently, to those in transit who're just trying to move on, and even those who just briefly come to Colombia for medical attention and then return to Venezuela," she explains.

The political scientist, who has also worked on migration at a national level, says that the media often highlight the negative impact of migration, such as crimes committed by foreign nationals.

But she says they rarely report on the positives - such as the way labour-intensive harvests on coffee and flower plantations have been saved by the influx of young workers.

What she would like to see is further investment in the integration of migrants - so the influx is seen not as a problem, but as an opportunity for the economic, cultural and gastronomic enrichment of the host nation.

"Some of those who have arrived have impressive skills," she says. "They have created businesses and have brought knowledge which has benefited the host cities and their inhabitants."