The US and some other Western nations were quick to recognize Guaido as the country's new leader, while Russia, Turkey, Iran, and China pledged their support for President Nicolas Maduro, who was sworn in for his second term earlier this year.
Venezuelan Attorney General Tarek William Saab announced Tuesday that he was launching a criminal investigation into Guaido's activities against President Maduro's socialist government, because of the unrest that followed Guaido's declaring himself the country's legitimate president.
The unusual arrival of a Russian passenger plane in Caracas has set social media abuzz with rumors about its mission after the Kremlin pledged to support its ally Venezuelan President Nicolas Maduro against a US -backed effort to drive him from office.
Kremlin said on Tuesday that USA sanctions against Venezuela's PDVASA are illegal and naked interference in Venezuela's internal affairs.
The United States has recognized opposition leader Juan Guaido as the interim president. Over 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 on Tuesday.
In a defiant broadcast on national television later the same day, Maduro said he would take legal action to challenge the sanctions and defend Citgo Petroleum, PDVSA's US refining subsidiary, which he accused the United States of trying to steal.
Analysts at RBC Capital Markets say Mexico and Iraq are instead most likely to benefit in the race to replace Venezuela heavy crude that is imported for processing at refineries on the U.S. Gulf Coast.
However, speculation of military action against him was fueled this week when Trump adviser John Bolton carried a notepad with the words "5,000 troops to Colombia".
China on Tuesday warned that the United States should bear responsibility for the consequences of its sanctions on Venezuela, in the wake of Washington's sanctions on the South American's vital oil exports.
Maduro went on state television on Tuesday to announce that he was beefing up the nation's defence by expanding Venezuela's civilian armed militia to 2 million members.
Oil prices finally rose on Wednesday after having at first shrugged off the risk of supply disruptions on the back of Washington's sanctions on Venezuela's oil industry amid the escalating political strife there.
If the Russians really are ferrying gold out of Venezuela, it would behoove Maduro to remember his Russian friends are very insistent on receiving timely payments on the enormous sums they have loaned him.
With Venezuela's economy in crisis, the country's debts worth billions have been piling up, especially from countries such as Russian Federation and China.
Russia expects Venezuela to have trouble servicing more than 3 billion dollars of debt to the Russian state, the Russian Finance Ministry said.
In Geneva, senior US and Venezuelan diplomats traded jibes at a disarmament conference.