Military officers still loyal to Mr Maduro have used a truck tanker and huge shipping container to block access to the Tienditas bridge which links Colombia and Venezuela at the key border town of Cucuta.
People cross into Venezuela over the Simon Bolivar worldwide bridge in Cucuta, Colombia February 4, 2019.
A growing number of European nations publicly backed Venezuelan opposition leader Juan Guaidó as his country's interim president, ratcheting up diplomatic pressure on President Nicolás Maduro to step down from power.
Their meeting comes amid massive protests in Venezuela aimed at pressing Maduro, the country's socialist leader, to vacate the presidency.
Canada has announced a humanitarian relief package for Venezuela.
The United States has pledged $20 million in aid that is to be gathered in Colombia, Brazil and an unnamed Caribbean island, but Guaido won't be able to bring it into Venezuela without the military's agreement.
Eurasia said U.S. oil sanctions are "set to have a broad impact" with the government facing "the prospect of running out of gasoline, which could serve as another social catalyst".
Mr Maduro has said the aid will be turned away by his the army, while Mr Guaido has called on the troops to allow it in to help struggling citizens.
Meanwhile the Government faces "serious questions" over what it will do to ensure any Venezuelan money illegally tied up in the United Kingdom is returned to the country's people, a former head of the foreign affairs select committee has said.
We won't invade North Korea: US envoy
Biegun said the USA still does not know what those measures would be, but hopes to find out soon. The Republican and Democratic leaders of the intelligence committee defended the officials.
At the same time, the group welcomed into the Lima Group Guaido's "legitimate government of Venezuela" and vowed to "recognize and work with" his representatives in their respective countries.
The group reaffirmed its support for Guaido and the opposition-controlled National Assembly, but rejected calls for a foreign military intervention, saying it supported a "peaceful transition".
Jeremy Konyndyk, a senior fellow at the Centre for Global Development, said Mr Maduro's continuing control of Venezuela's military and all the territory meant getting aid across the border will be hard but warned against politicising the assistance.
Guterres was encouraged by last Saturday's peaceful protest, saying "Our strong call is to avoid all forms of violence, that, of course, have no objective and do not benefit anyone".
Labour leader Jeremy Corbyn - a long-standing admirer of Nicholas Maduro's socialist predecessor Hugo Chavez - has strongly condemned outside interference in Venezuela "whether from the U.S. or anywhere else".
European Union member states had indicated that if no new elections are announced, they would take action within the next few days, including on the issue of recognition of the country's leadership in accordance with Article 233 of the Venezuelan constitution.
Maduro, 56, has repeatedly accused the United States of fomenting a coup. He is supported by China and Russian Federation, while Slovakia on Wednesday joined Italy in defying the coordinated action of European Union nations and the United States.
In his State of the Union address Tuesday night, President Donald Trump reaffirmed U.S. support for Guaido, saying "we stand with the Venezuelan people in their noble quest for freedom".