The Obama administration secretly airlifted $400m in cash to Iran in an unmarked cargo plane earlier this year in what Republicans allege was a “ransom payment”.
Wads of Euros and Swiss francs stacked on wooden pallets were delivered in January just as five American prisoners were granted clemency by Tehran, unnamed sources told the Wall Street Journal.
Procured from central banks in the Netherlands and Switzerland, the cash payment was not disclosed when President Obama announced the release of the hostages on January 17.
Hostages, including Washington Post journalist Jason Rezaian, were flown out of Iran on a private jet to Switzerland. (AAP)
Republicans seized on the revelations, accusing the Obama administration of breaking with US policy by making a “ransom payment” to Iran.
The White House has denied any link between the payment and the release of hostages, saying it was the first instalment in $1.7b owed to Iran over a failed arms deal just before Ayatollah Khomeini seized power 37 years ago.
“This $400 million is actually money that the Iranians had paid into a US account in 1979 as part of a transaction to procure military equipment,” said White House spokesman Josh Earnest.
“It is against the policy of the United States to pay ransom for hostages.”
Explaining the unusual manner of the cash delivery, Earnest said the “fact of the matter is the United States does not have a banking relationship with Iran”.
Late last year, Washington brokered a deal with Iran to lift economic sanctions in exchange for the rogue nation dismantling its nuclear program.
The Obama administration hailed the deal as a breakthrough for steering Iran towards disarmament, while Republicans said Iran would use the multi-billion-dollar windfall to fund terrorism.
Donald Trump has issued a statement overnight calling the cash delivery a “terror money airlift” and “money that will undoubtedly find its way into the hands of terrorists”.