Soldiers from the Venezuelan national guard have left their posts ahead of an opposition-led effort to bring aid into the country, Colombia's migration agency said.
In a separate development, Venezuelan troops have fired tear gas at people looking to cross into colombia to work.
Tensions have been rising over a row about the delivery of humanitarian aid.
President Nicolás Maduro said the border with colombia is partly closed to stop aid being delivered.
But self-declared interim president Juan Guaidó has vowed that hundreds of thousands of volunteers will help bring in the aid deliveries, which include food and medicine, on Saturday.
What's the latest?
Local media report people jumping the barricades to cross the border at the Venezuela-Colombia border, while opposition MPs have posted defiant messages on social media denouncing the use of force.
The BBC's Orla Guerin, on the Colombia border, said Venezuelans were begging soldiers to be allowed to cross.
Pictures show protesters burning outposts and throwing rocks at soldiers and riot police in border areas.
Reporters at the scene have announced Mr Guaidó's arrival at the Tienditas bridge on the Colombian side of the border. He was accompanied by the country's president, Iván Duque.
Mr Guaidó urged the military to allow aid trucks to enter, calling on…