Venezuela President Nicolas Maduro threatened to close the border with Colombia on Thursday as opposition leader Juan Guaido and some 80 lawmakers ran a gauntlet of roadblocks trying to get to the frontier to receive humanitarian aid.
"This is the real humanitarian aid of Venezuela", said Ramirez.
Guaido has named Saturday as the deadline for the aid to cross the border. Pence will meet with Colombian President Ivan Duque as well as Venezuelan families who have sought refuge outside the country.
Opposition leaders led by Juan Guaido are vowing to bring in United States supplies of emergency food and medicine to dramatise the country's hardships under Mr Maduro, who has said the country doesn't need such help.
Wednesday's rally in Caracas gathered just a couple of dozen buses and pick-up trucks in Guaido's support.
Maduro's government is suspicious of the U.S. stated plan to provide humanitarian assistance to Venezuelan opposition.
One opposition lawmaker in southeastern Bolivar state said he and some 20 other politicians would also travel to the border with Brazil.
"It will be completely closed until otherwise notified, the land border with Brazil".
The White House said Pence will deliver remarks to the 14 nations that are part of the "Lima Group" in Bogota about addressing the humanitarian crisis in Venezuela and ongoing USA efforts to deliver aid to the country.
Guaido invoked the constitution to assume an interim presidency on January 23 and denounces Maduro as an usurper who has devastated the country. United States envoy for Venezuela Elliott Abrams has a record of using humanitarian convoys to smuggle arms to Latin American countries targeted for regime change by Washington, and Caracas says he is now trying to follow the same script in Venezuela.
Maduro's decision follows the action taken by opposition leader Juan Guaido in defiance of Maduro.