The anti-Maduro protests on Wednesday were far smaller than the massive outpouring over the weekend, and the government repression in recent days may have discouraged a broader attendance.
Earlier on Wednesday, President Trump spoke to Guaido, according to White House press secretary Sarah Sanders.
Pompeo said the certification would "help Venezuela's legitimate government safeguard those assets for the benefit of the Venezuelan people".
The leaders also agreed to regular communication in support of Venezuela's path back to stability and to rebuild strained relations between both countries. Maduro was supported by Russia, Bolivia, Iran, Cuba, Nicaragua, El Salvador and Turkey.
"We won't allow a Vietnam in Latin America", Maduro said.
Bogota and Washington have routinely denied that, while foes say Maduro uses such accusations as a smokescreen when in trouble.
Though the Venezuelan was reprising an old allegation that critics scoff at as a smokescreen, there was speculation of military plans after Trump adviser John Bolton appeared on Monday with a pad showing the words "5,000 troops to Colombia".
Guaido is banned from leaving the country until a preliminary investigation is complete after he "caused harm to peace in the republic", court head Maikel Moreno said on January 29.
Maduro created a rival legislature - the Constituent Assembly - made up exclusively of his supporters.
A former union leader, bus driver and foreign minister, Mr Maduro has overseen a shrinking economy and the migration of three million Venezuelans fleeing shortages and hyperinflation.
The U.S. State Department, meanwhile, said that Americans shouldn't travel to Venezuela, warning of unrest, the threat of being arbitrarily arrested and of mass demonstrations occurring with little notice.
The already distressed nation is likely to face even tougher times ahead after the USA imposed sanctions Monday on Venezuela's state-owned oil company, potentially depriving the Maduro government of $11 billion in export revenues over the next year.
But for now, the military high command remains loyal to Maduro.
Opposition leader and self-proclaimed "acting president" Juan Guaido (center), marches surrounded by students during a protest he convened against the government of President Nicolas Maduro, outside Venezuela's Central University (UCV) in Caracas.
"I am ready to sit down at the negotiating table with the Opposition so that we could talk for the good of Venezuela", Maduro told the Russian news agency in an interview.
"I won legitimately", he said of last year's election.
"Presidential elections in Venezuela have taken place, and if imperialists want new elections let them wait until 2025", he said in an apparent reference to Washington.
More than 40 people are believed to have been killed in political violence last week, including 26 shot by pro-Government forces, five killed in house raids and 11 during looting, United Nations human rights spokesman Rupert Colville said. Hundreds have also been arrested, including children.
Maduro also claimed that US President Donald Trump had ordered the government of Colombia to assassinate him.