Floods and landslides have killed more than 80 people and left at least 60,000 homeless in Venezuela and Colombia.
Venezuela's south-western state of Merida was badly hit
Around 53 Venezuelans have died and the homes of some 21,000 people destroyed, Interior Minister Jesse Chacon said.
In neighbouring Colombia, at least 33 people were killed and more than 40,000 left their homes, mainly in Norte de Santander and Santander provinces.
Riverside shanty town had been worst hit by the week-long storm that has pounded the region, rescuers said.
"This has been very unusual. It doesn't rain like this normally at this time of year," said Colombia's emergency officer, Eduardo Jose Gonzalez.
Helicopters are delivering supplies to remote mountain areas, as well as rescuing those left stranded.
The south-western state of Merida was worst hit in Venezuela. At least 32 people were reported killed and some 50 people were still missing, officials said.
People living in shanty towns based in the steep mountain peaks of the Mocoties River were drowned when the banks overflowed. Many were women and children.
The bodies of victims floated for miles downstream, firefighters said.
Around the town of Santa Cruz de Mora, roads were blocked and remote villages were left without water, food and electricity. Vital crops such as potatoes and coffee were washed away.
Colombia declared a state of emergency on Sunday, and President Alvaro Uribe promised "the necessary resources to take care of the people".
Governor of Santander province Didier Tavera described the situation as "awful", and said on Monday at least 40 people were still missing.