> A presidential, strong-president, or single-executive system is a form of government in which a head of government (usually titled “president”) heads an executive branch that derives its authority and legitimacy from a source that is separate from the legislative branch. The system was popularized by its inclusion in the Constitution of the United States.
Giving the benefit of the doubt here to the OP, but from https://en.wikipedia.org/wiki/Presidential_system we have this definition:
> A presidential, strong-president, or single-executive system is a form of government in which a head of government (usually titled “president”) heads an executive branch that derives its authority and legitimacy from a source that is separate from the legislative branch. The system was popularized by its inclusion in the Constitution of the United States.
So perhaps “The US also has a strong-president system” as per the Wikipedia definition is what the reference was towards, which would have been accurate. Skimming over https://en.wikipedia.org/wiki/Politics_of_El_Salvador and https://en.wikipedia.org/wiki/President_of_El_Salvador make me believe that this is also true of El Salvador (since the Presidency there also derives authority from the Constitution and thus separately from the legislative branch).