Ecuador announced Thursday it was tightening entry requirements for Venezuelans to help deal with a wave of immigration from the crisis-torn country.
Interior Minister Mauro Toscanini said Venezuelans entering the country will be required to present passports from Saturday.
Up to now, Venezuelan nationals only had to present ID cards at the border, where they received a letter that allowed them to circulate freely in Ecuador.
The move is part of Quito's response to the crisis after it declared a state of migration emergency last week.
The UN said more than half a million Venezuelans have crossed into Ecuador this year alone, after passing through Colombia.
Many continue on to Peru and Chile in search of work. Peru said 5,100 Venezuelans entered the country last Saturday, a record for a single day since the crisis began.
"With the purpose of guaranteeing both the safety of Venezuelan citizens and the security of our territory...from this Saturday we require that all persons entering Ecuador submit their passport," Toscanini told reporters.
The minister urged the government of President Nicolas Maduro "to make all political, and above all social efforts, at once, so that its citizens do not have to go through the very difficult situation of leaving their country."
UNHCR said Ecuador's state of emergency declaration would help mobilize more resources and announced that the UN was also stepping up its regional response.
Venezuelan President Nicolas Maduro has tightened his grip over opponents whom he has branded as agents of a foreign-backed plot.
Caracas's diplomatic isolation has intensified, with the country in the grip of staggering hyperinflation, shortages of food and medicine.