The Cuban government on Thursday denied allegations by the United States and Venezuela's opposition that Cuban troops have been stationed in Venezuela and are advising the country's army.

"Cuba does not have troops nor does it have soldiers in ... Venezuela," Foreign Minister Bruno Rodriguez said at a press conference in Havana.

"It is a vulgar calumny that I again deny," the minister said, calling on the US to provide evidence of the allegations.

Washington has blamed Venezuela's political and economic crisis partly on Cuba, saying support from Havana has helped President Nicolas Maduro stay in power.

The support of the Venezuelan army has also allowed Maduro to remain at the helm.

Dozens of countries having sided with opposition leader Juan Guaido, who is pressuring the president to resign.

Eduardo Stein, the joint representative of the UN refugee agency UNHCR and the International Organization for Migration for Venezuelan migrants, meanwhile said that about 5,000 people are leaving Venezuela daily to flee the crisis.

If that rhythm is maintained, more than 5 million Venezuelans will have emigrated by the end of the year, Stein said at a joint press conference with Colombian Foreign Minister Carlos Holmes Trujillo in Bogota.

Colombia alone has received more than 1 million Venezuelans fleeing hyperinflation, food and medicine shortages and political unrest.

Stein and Holmes Trujillo called on the international community to step up its financial support to countries receiving Venezuelan migrants.