Ruling left-wing SYRIZA party issued its own statement last week in which it expressed support for "the legitimate President" Maduro.
The Trump administration warned of "serious consequences" after Venezuela's government moved to freeze the bank accounts of self-proclaimed interim president Juan Guaido on Tuesday, while state-run oil company PDVSA sought to sidestep USA sanctions.
The sanctions threatened to hasten PDVSA's unraveling.
The move is expected to block $7bn in assets and result in $11bn of lost export revenue over the next year.
"The goal of sanctions is to change behaviour", Treasury Secretary Steven Mnuchin told reporters at the White House.
Monica de Bolle, a senior fellow at the Peterson Institute for International Economics, said the Maduro regime probably wants to keep the accounts so that Venezuela's creditors don't try to take those assets. "Otherwise we will not be buying it".
The sanctions bar state-owned oil company Petroleos de Venezuela SA from collecting proceeds from crude sales to USA refineries.
On January 23, 696 people were detained across the country, the highest daily number of detentions in Venezuela in 20 years.
Worldwide challenges to the legitimacy of President Nicolas Maduro's government are starting to bite harder.
Many people are going hungry, while inflation has skyrocketed and left basic goods unaffordable.
Italian Prime Minister Giuseppe Conte earlier called for national reconciliation and democratic process in Venezuela and expressed concern about the possibility of further escalation of violence.
Asked to explain the words, the White House said in an email that: "As the President has said, all options are on the table".
The US has responded to the ongoing crisis by introducing sanctions on state-run oil company PVDSA.
Mexico and Iraq are instead most likely to benefit in the race to replace Venezuela heavy crude imported for processing at refineries on the U.S. Gulf Coast, analysts at RBC Capital Markets said in a report.
Frank Holder, the head of Berkeley Research Group's Latin American practice, said Mr Guaido could face difficulties in appointing a Citgo board against the wishes of its parent company.
Maduro, in response, said he was breaking ties with the US, giving diplomatic personnel 72 hours to leave the country.
The United States imposed sanctions on Venezuela and PDVSA in 2017 that prevented Citgo from repatriating dividends to its parent company.