President Donald Trump has banned US citizens and companies from using Venezuela’s new cryptocurrency, the petro, as he steps up the pressure on the government of President Nicolas Maduro.

In a separate move, the administration also slapped sanctions on four current and former senior Venezuelan officials accused of corruption and mismanagement.

On Monday, Trumped signed an executive order barring any US-based financial transactions involving the petro as officials warned that it was a “scam” by the government in Caracas to further undermine democracy in Venezuela.

“The ‘petro’ is a desperate effort by a corrupt regime to defraud international investors,” a senior US administration official told reporters.

In the executive order, Trump said the cryptocurrency was an “attempt to circumvent US sanctions” previously imposed.

In February, cash-strapped Venezuela became the first country to launch its own version of bitcoin in a move that Maduro celebrated as putting his country at the world’s technological forefront.

The petro is backed by Venezuela’s crude oil reserves, the largest in the world, yet it has arrived on the market as the country sinks deeper into an economic crisis marked by soaring inflation and food shortages that have forced residents to line-up for hours to buy common products.

“Investing in the ‘petro’ should be viewed as directly supporting this dictatorship and its attempts to undermine the democratic order in Venezuela,” the US official said.

Venezuela rejected the sanctions, which it says are illegal under international law.

“These unilateral sanctions ... constitute a new imperial aggression aimed at intensifying the attack on our people,” the government said in a statement.

The order came as the Trump administration actively explores options to sanction Venezuela’s oil sector.

The senior administration official said the sanctions against the four Venezuelan officials were not directly linked to the cryptocurrency issue.

The order freezes any assets they may have in US jurisdictions and bars Americans from doing business with them.

The four include Americo Alex Mata, a director of Venezuela’s National Bank of Housing and Habitat and co-ordinator of Maduro’s 2013 campaign, Willian Antonio Contreras, the head of the body that oversees price controls in the country, Nelson Reinaldo Lepaje, the head of the Office of the National Treasury, and Carlos Alberto Rotondaro, the former president of the Board of Directors of the Venezuelan Institute of Social Security.