Republican presidential nominee Donald Trump on Wednesday blasted the Obama administration over a report in the Wall Street Journal which said it secretly funneled $400 million in cash to the Iranians in January, around the time four American prisoners were released from Tehran.

Trump called the incident a “scandal”, and pointed out that negotiations opened when his Democratic rival Hillary Clinton was serving as Secretary of State.

“Our incompetent Secretary of State, Hillary Clinton, was the one who started talks to give 400 million dollars, in cash, to Iran. Scandal!” Trump said, according to Breitbart.

In a speech in Daytona Beach, Florida later on Wednesday, Trump said, “We have a president who is frankly incompetent.”

The State Department has denied the money paid to Iran was a ransom payment in exchange for the American hostages.

“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,” State Department spokesman John Kirby said.

“Not only were the two negotiations separate, they were conducted by different teams on each side, including, in the case of The Hague claims, by technical experts involved in these negotiations for many years,” he added.

The Wall Street Journal report, however, noted that press reports in Iran quote Iranian officials who described the payment as ransom.