WASHINGTON, April 5 (Xinhua) -- The U.S. Treasury on Friday listed Venezuela-related companies and vessels as its designated targets in a new round of sanctions to pile up pressure on the Maduro government.

The two companies blacklisted operated in the oil sector of the Venezuelan economy and were accused of shipping oil to Cuba, according to a statement released by the Treasury. One vessel owned by one of the companies was also designated.

Besides, the Treasury designated 34 vessels that belonged to Petroleos de Venezuela S.A. (PDVSA), a Venezuelan state-owned oil company that was added to America's blacklist in January.

As a result of the sanctions, all property of those entities that are in the United States would be blocked. Also, U.S. persons are generally prohibited from all dealings that involve any property of theirs.

"Treasury is taking action against vessels and entities transporting oil, providing a lifeline to keep the illegitimate Maduro regime afloat," said Treasury Secretary Steven Mnuchin in the statement.

Mnuchin also accused Cuba of being "an underlying force fueling Venezuela's descent into crisis." Washington has singled out Cuba and Russia as chief backers of the Venezuelan government.

The United States has been pursuing a policy of economic sanctions and diplomatic isolation against the Venezuelan government in support of the opposition leader Juan Guaido. The Trump administration recognized Guaido as the nation's "interim president" on Jan. 23, days after incumbent President Nicholas Maduro was inaugurated for a second term.

In response to Washington's support for Guaido, Maduro announced that he was severing "diplomatic and political" ties with the United States.