According to briefings of US and European officials, the Obama administrations secretly funneled 400 million dollars in cash to the Iranians back in January, as reported by The Wall Street Journal.
The revelation was particularly notable in that it coincided with the release of four American prisoners being held by the Iranians, leading to speculation that the payment was, indeed, a ransom payment.
In turn, if this is true, the entire foundation of the Iran Nuclear Deal, which presumes an already friendlier relationship with Iran, is thrown into question.
Obama dismissed the claims of a ransom payment, claiming it was simply the right time to pay off an old debt from a decades-old failed arms deal: “with the nuclear deal done, and prisoners released, the time was right to resolve this dispute as well,” he said.
State Department spokesman John Kirby also dismissed claims of a connection between the release of the prisoners and the payment: "As we’ve made clear, the negotiations over the settlement of an outstanding claim…were completely separate from the discussions about returning our American citizens home," he said. “Not only were the two negotiations separate, they were conducted by different teams on each side."
Nevertheless, US officials have acknowledged that the Iranian negotiators had said that they wanted something tangible to show for the prisoner release. Further, according to Iranian press reports, Iranian defense officials have portrayed the cash shipment as a ransom payment, as reported by WSJ.