The US has imposed sanctions on Venezuela's state-owned oil firm PDVSA and urged the country's military to accept a peaceful transfer of power.
National Security Adviser John Bolton said President Nicolás Maduro and his allies could "no longer loot the assets of the Venezuelan people".
The sanctions aim to transfer control of Venezuela's oil wealth to forces that oppose socialist dictator Nicolas Maduro and deprive the strongman of resources that could prolong his grip on power.
Last week, the opposition leader of Venezuela's National Assembly, Juan Guaido, named himself interim president amid street protests.
President Donald Trump soon recognized Guaido as the nation's leader and his administration has been marshaling international support for the opposition figure since then.
Maduro, having recently started another term following highly disputed elections, is refusing to back down.
He is supported by the country's minister of defense and Russia.
The US and more than 20 countries have recognised opposition leader Juan Guaidó as interim president.
The move comes after a turbulent week for Venezuela that has created a standoff over the country's leadership.