El Salvador has been given a Category 2 rating by the US FAA under its International Aviation Safety Assessment (IASA) programme, meaning the country does not comply with ICAO safety standards.
The FAA says the rating follows an "evaluation of information currently available on the country's civil aviation authority". It adds that it is working with El Salvador to address safety and operational oversight issues.
"The FAA believes that El Salvador is committed to internationally agreed-upon safety oversight obligations as evidenced by the country's strong support of the new Central American Agency for Flight Safety (ACSA)," it says.
"ACSA is part of the Central American Corporation for Air Navigation Services (COCESNA) agency; its primary responsibility will be to provide flight safety oversight for the region."
Last month the FAA said it had changed the way it classifies other civil aviation authorities' compliance with ICAO standards.
Until the change the agency graded countries based on three categories: Category 1, meaning full compliance with ICAO standards; and Category 2 and Category 3, both of which indicated non-compliance with ICAO standards.
The only difference between Category 2 and 3 was that the former meant airlines from a country in question operated services to the USA while the latter did not have such services.
In changing the system to have only Category 1 and Category 2 gradings - the latter being non-compliance - the FAA said the old system gave a false impression that Category 2 countries had better safety oversight than Category 3 countries.