Venezuelans fleeing acute food shortages, high crime and political unrest have flooded across the border to Colombia in recent years. 

Some visit just to buy or sell groceries, while others begin lives from scratch, often working informally and without visas.

Last year Colombia extended permits for Venezuelans in a humanitarian measure - the government estimates there are some 470,000 Venezuelans in the country.

There has long been diplomatic tension between the neighboring governments. 

Santos has accused Venezuelan President Nicolas Maduro of destroying democracy in Venezuela, while Maduro has said Colombia is part of an international conspiracy seeking to overthrow his government.

TRT World'sDimitri O'Donnell reports from the town of Cucuta at the border with Venezuela.