The chant, as officially translated by the government itself [1] means "Down with the USA". "Death to" is a purposeful (literal) mistranslation to make it sound like it's a genocidal statement.
Is that to say the Islamic Republic of Iran don't necessarily want to eradicate the USA but merely want to see its downfall? I don't have much sympathy for that; it's not like there's some more liberal, more democratic, alternative superpower waiting in the wings.