PDVSA bonds could be excluded from key indexes, also impacting sovereign paper, Bank of America Merill Lynch (BAML) said.
The country sends about 40 per cent of its 1.3 million barrels per day of oil exports to the United States, RBC noted.
The Venezuelan opposition figure has suddenly rocketed to worldwide acclaim in the past week, after swearing himself in as president of the country in a direct flouting of Maduro at the front of large anti-government protests - which have been met with pro-government rallies.
Russia's support for Maduro has its limits, however, as the Russian Finance Ministry on Tuesday made it clear that Venezuela is expected to make payments on time for its billions of dollars in Russian loans.
"While the general belief is that Canadian heavy barrels should benefit with the demise of Venezuela, the notional degree of market share up for grabs for Canada is not as large as for competing countries", they said.
This followed a 2-percent price jump the previous session, when markets first digested the U.S. sanctions on Venezuela's oil exports.
The step pushed up oil prices on Monday, but markets appeared more relaxed on Tuesday as the sanctions only impact Venezuelan supply to the United States.
Juan Guaido, Venezuela's self-proclaimed interim president.
Brazil and the Organization of American States recognized Guaido as Venezuela's leader prior to his formal announcement. China, Cuba, Bolivia and Turkey also back him.
With strongman President Nicolas Maduro losing control of the country's already-scant finances and reserves thanks to US sanctions, who can put his hands on the nation's estimated 200 tons of gold at home and overseas has become a key question.
Similarly, Russian Foreign Minister Sergey Lavrov said Tuesday that the new restrictions imposed against Caracas were effectively an attempt to confiscate the country's state assets.
"The legitimate government of Venezuela called these sanctions illegal".
The United States has refused to rule out military intervention in Venezuela and Donald Trump's National Security Advisor John Bolton was even photographed on Monday at the White House holding a notepad with the scrawled line: "5,000 troops to Colombia".
Opposition leader Guaido, on the other side, called on the European Union (EU) Wednesday to level "more sanctions" against Maduro's government, in an interview with German daily Bild.
Maduro called the sanctions "criminal" and vowed to challenge the U.S.in court. We will always be moving forward in this area. Mnuchin said Venezuela can get relief from the sanctions when control of the oil company is turned over to Guaido.
His country counts on strong support from China and Russian Federation for economic development, he added.
"There is cooperation every month. And this is normal, there is nothing extraordinary here", the president added.
With the crisis deepening a showdown between Washington and Moscow across various global flashpoints, Maduro also expressed "pleasure and gratitude" for Putin's help.
"I am ready to sit down at the negotiating table with the opposition so that we could talk for the good of Venezuela", said Maduro, 56.
Venezuela has suffered from economic turmoil and a humanitarian crisis under Maduro.