According to Alejandro Zelaya, businesses will not be penalized if they do not accept bitcoin.
The ratings agency warns there are additional regulatory and operating risks tied to the country adopting bitcoin as legal tender.
The rating agency said that the law and other policy decisions had “weakened governance” and increased tensions with other countries.
La adopción de esa criptomoneda como de curso legal podría ayudar a impulsar la economía del país, dice nuestra columnista, pero hay riesgos si el gobierno se excede en la concesión de nuevos préstamos.
The bank points to bitcoin's illiquid nature, volatility and U.S. dollar conversion risk as major limitations for its use as legal tender.
The poll, which took the results from 1,233 people between July 1 and July 4, also showed 46% knew "nothing" about bitcoin.
Bitcoin's jump coincides with announcements made by El Salvador's president on Thursday evening.
Crypto ATMs are seen as a way for people to interact with the physical world, particularly those who are not well-versed in cryptocurrencies.
President Nayib Bukele made the announcement during a national address on Thursday.