Bogota, Colombia - A tighter squeeze on Venezuela from recent US sanctions will only mean more people pouring into neighbouring Colombia, humanitarian groups warn, even as other South American countries are closing their doors on refugees.
Colombia sees hope quickly fading that it can stem the steady flow of migrants, even as it grapples with the presence of 1.4 million Venezuelan migrants already on its border.
"There is fear of the impact that the new US government sanctions will have on life in Venezuela," said Marianne Menijvar, Colombia director for the International Rescue Committee, which runs facilities at the border.
"Since halfway through last week and the weekend we've seen increased numbers of Venezuelans crossing," she told Al Jazeera.
She also said that part of the spike in Venezuela migration may also include a rush to Ecuador, before new immigration restrictions take effect there on August 25.
That could mean more migrants heading to Colombia after the deadline.
Negotiations have broken down between Venezuelan President Nicolas Maduro and the US-backed opposition, over the country's future.
Squalid living conditions
Colombia has welcomed all immigrant children from Venezuela into its school, though many still linger on waiting lists.
It also extends free healthcare to the Venezuelan migrants, although only in an emergency situation, including birth. It has also issued about 700,000 special permits for immigrants to work.
But many young Venezuelan families still sleep in the streets or in squalid conditions throughout all big cities of Colombia.
More than four million people have fled Venezuela following its economic collapse and political turmoil.
The Organization of American States expects that the exodus will further rise in 2020, exceeding the 6.7 million people who fled Syria's civil war.
Colombia hosts more Venezuelans than any other nation.
"More come every day," said Rut Guerra, a 20-year-old Venezuelan who has lived for four months in a pop-up community of brick shacks on Bogota's southern fringe of Soacha.
"The question is, when do we [in Venezuela] hit bottom? We still haven't hit bottom."
Many young adults in Soacha arrived from Venezuela on foot.
They then use the money they saved from their journey to buy bus tickets for their spouses or children to join them from the border.
Their communities have since expanded as many migrants save up to bring their families and friends out of the crisis back home.
Such communities have sprouted throughout Colombia since the humanitarian crisis began in Venezuela.
The attention of humanitarian organisations has not yet turned to these budding problem zones yet, said Fabian Caidenar, a migration coordinator with Red Cross Colombia.
"It's all focused on the border. People need to realise that we have a problem in the interior and it's permanent," he said during a free healthcare clinic for Venezuelan migrants in Soacha. "It will keep growing."
Colombia, the staunchest US ally of Latin America, stood enthusiastically with Washington in recognising opposition leader Juan Guaido as Venezuela's rightful government when he declared himself as such in January.
Colombia invested fully in the movement, hosting US and Venezuelan opposition officials in February to challenge Maduro at the border with a convoy of US humanitarian aid in February.
Back then, leaders expected that the change in Venezuela was just about to come. Yet in six months since, the opposition has not been able to wrangle power from Maduro.
Nor have the US sanctions seemed to affect his grip on the country.
Suffering most from the fallout of the crisis, Colombia does not seem to know how to handle the situation.
"They've basically pinned themselves into a corner in terms of Venezuela policy," political analyst Sergio Guzman, head of Colombia Risk Analysis, told Al Jazeera.
"We're in a situation where if none of the parties change their position, we're going to be going down the same road for a very long time."
The intensifying US sanctions against a defiant Latin American administration raise many comparisons to Cuba, and some Colombians wonder if they should settle in for a nearly 60-year standoff with little alleviation of the conditions driving migration.
US President Donald Trump's Venezuelan sanctions, however, stop short of the full Cuban style embargo barring all business with the nation. The US sanctions bar commerce with the Venezuelan government and its subsidiaries.
They could still have a crippling effect on a nation with a state-run economy already gasping for life.
US sanctions began targeting the Venezuelan economy in January this year with rules isolating Venezuelan state-run oil company PDVSA.
Before that, they had honed in on individuals associated with Maduro. Trump's escalation last week brought the entire Venezuelan state into the targeted fold and prohibited foreign actors from working with Maduro as well.
"Every move by the foreign countries, and the US in particular, to make it more difficult to trade or do business with Venezuela will make conditions there worse," Ivan Briscoe, Latin America director for the International Crisis Group told Al Jazeera.
"Colombia will have to deal with humanitarian shockwaves that it is not prepared to deal with."