The UN refugee agency based in Geneva said the number of Venezuelans who have sought asylum has shot up 2,000 percent since 2014, but the most dramatic increases have ocurred over the last 14 months.
With the country's economic and political crisis intensifying, UNHCR has drawn up a "regional response plan that covers eight (surrounding) countries", spokesperson Aikatarina Kitidi said.
"In view of the situation in Venezuela, it is crucial that people are not deported or forcibly returned there," she added.
Asked if the UN had received reports of deportations or forced returns, Kitidi did not answer directly, saying only the agency was calling for "solidarity" among nations in the region in responding to Venezuelans in need.
An influx of Venezuelans has reportedly stirred tensions in Brazil, notably in the city of Boa Vista which has received 40,000 people, raising its population by more than 10 percent.
Hundreds of Venezuelans there have been sleeping on the ground for months, while using restrooms in gas or bus stations.
UNHCR warned that an increasing number of Venezuelans, especially those living abroad without legal protection, are "vulnerable to exploitation, trafficking, violence, sexual abuse, discrimination and xenophobia".
The UN agency does not have a precise figure for those who have fled the crisis in Venezuela.
Regarding only those who have filed refugee claims, UNHCR said the figure stood at 145,000 since 2014 – but 94 percent of those claims have been recorded since the start of 2017.