Farhadi, who won an Oscar for The Separation in 2012, said he would not attend even if he could.
The Salesman is nominated for best foreign language film at the Oscars, but it remains unclear whether the Iranian cast and crew can attend the Hollywood ceremony.
It adds that “as one [individual but highly symbolic] consequence” of the ban, Farhadi would no longer be allowed to enter the US.
Michael Moore tweeted: “To our Muslim neighbours in the world: I & tens of millions of others are so very sorry.