"President [Nicholas] Maduro has informed the international community about the opening of the land border with Brazil starting today. We will establish border control that will strengthen economic cooperation and benefit the two peoples," he said.
Venezuelan authorities ban the entry of unauthorised aid, believing that Washington wants to use it to arm opposition and oust the Maduro government from power.
The political standoff in Venezuela escalated on 21 January when Guaido proclaimed himself interim leader of the country, in what was supported by a number of countries, including the US.
Maduro, in turn, accused the United States of trying to orchestrate a coup in order to install Guaido as its puppet. Russia, China, and a number of other countries have voiced their support for Maduro as the only legitimate president of Venezuela.