From the Wikipedia article on the slogan [1]

> معلوم هم هست که مراد از «مرگ بر آمریکا»، مرگ بر ملّت آمریکا نیست، ملّت آمریکا هم مثل بقیّهٔ ملّتها [هستند]، یعنی مرگ بر سیاستهای آمریکا، مرگ بر استکبار؛ معنایش این است.

"It is also clear that 'Death to America' does not mean death to the American people; the American people are like other nations, meaning death to American policies, death to arrogance; this is what it means.

Translation by Claude; my Persian is only basic-to-intermediate but this seems correct to me.

[1] https://fa.wikipedia.org/wiki/%D9%85%D8%B1%DA%AF_%D8%A8%D8%B...