The United States on Monday said it had been unable, due largely to logistical reasons, to accept an Iranian request for assistance following a helicopter crash over the weekend that killed President Ebrahim Raisi, as Washington offered its condolences.
Archived version: https://archive.ph/kN7hp
Hmm, the closest US asset would probably be the Black Hawk group stationed at Harir Air Base in Iraq, which is ~450km from the crash area. That should be within the operating range *with wingtip tanks. If they didn’t have the external fuel tanks ready to equip, or if they just didn’t have a crew available (because it’s the weekend) then obviously they couldn’t make it.
It’s also entirely possible that the US military wanted some official assurance that any units crossing the border would be treated as friendlies (especially in current context), and that just didn’t happen fast enough to participate in the search & rescue.
They needed an official word from Raisi but he was indisposed at the time.
Kinda like the opposite of out-of-network doctors at your ER.