Florida senator Bill Nelson has joined the ranks of those hitting out at Venezuela's recently launched petro token.

In a letter sent to Treasury Secretary Steven Mnuchin on Monday, Nelson said he was “concerned by recent reports” that Venezuela, as well as Russia, are planning to use cryptocurrencies to get past economic sanctions.

Focusing on Venezuela's president, in particular, he noted that Nicolás Maduro “is responsible for persistent human rights violations, political repression and the jailing of opponents, undermining democratic institutions, corruption, and widespread economic deprivation."

Nelson continued:

The senator concluded his letter with several questions for Mnuchin, asking what the Treasury Department is already doing to prevent Maduro from raising funds via the petro, what it will do to crack down on exchanges which are not following sanctions and whether the department needs new authority to fight attempts to avoid sanctions, among others.

With the letter, he joins senators Bob Menendez and Marco Rubio in requesting that Mnuchin limit the use of the petro. In late January the two co-wrote a similar letter asking how the department could crack down on Venezuela’s attempt to bypass sanctions. Menendez’s office later said he was planning to follow-up with the department.

Venezuela debuted the controversial petro last month, launching a pre-sale near the end of February.

The oil-backed token is intended to act as legal tender within the country, by order of the president, though it cannot be exchanged for the existing Venezuelan bolivar. President Maduro has claimed to have raised as much as $5 billion through the pre-sale, but has not released any evidence to support this.

Bill Nelson image via Shawn P. Eklund for the U.S. Navy/Wikimedia Commons