Republican presidential nominee Donald Trump on Wednesday lambasted President Barack Obama and Hillary Clinton for allowing the Iranian regime to humiliate the U.S. by delivering a secret $400 million payment to Iran in January.

“We have been humiliated by President Obama and his policies. We have been humiliated by the Iran deal to start off with, where they get back $150 billion,” Trump said at a rally in Daytona Beach, Florida on Wednesday. “We’ve been humiliated as a country when they took our sailors, they forced them to their knees. And the only reason we got them back is because we hadn’t paid the money yet. And that’s the only reason we got them back. Otherwise they would have had to wait until I became president.”

The Republican nominee was referring to a Wall Street Journal report that the Obama Administration sent $400 million dollars – in “wooden pallets stacked with euros, Swiss francs and other currencies” – to Iran at the same time four American hostages were released. The paper quoted Senator Tom Cotton, a Republican from Arkansas, as accusing the Obama administration of paying a “ransom to the ayatollah for US hostages.”

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

The White House insisted the payment was part of the deal that put an end to a longstanding financial dispute between the U.S. and Iran, and was delivered in cash because “the U.S. doesn’t have a banking relationship with Iran.”

Earnest also addressed concerns that the money delivered to Iran could be used to fund terror activities or to violate the nuclear deal. “The U.S. continues to have concerns with some of Iran’s nefarious activities,” Earnest said at the daily press briefing. “The president was quite forward leaning in advance of the deal being acknowledged that we know that Iran supports terrorism, we know that Iran supports Hezbollah and the Assad regime, and it certainly is possible that some of the money that Iran has is being used for those purposes too. But the bulk of the money has been going to shoring up their economic weakness, exactly how we predicted.”

But Trump insisted the money will be used to fund terrorism. “Where does that money go? Who gets that money?” he asked. “I doubt it’s the people of Iran. I doubt it.”

Linking Clinton to the nuclear deal, Trump added, “Iran is now a power, and they’re going to have nuclear weapons much sooner than you think.”

Republican National Committee (RNC) Chairman Reince Priebus said in a statement, “The Obama-Clinton foreign policy not only means cutting a dangerous nuclear deal with the world’s number one state sponsor of terrorism, it also means paying them a secret ransom with cargo planes full of cash… While our weak posture toward Iran undermines our interests, we cannot forget that Hillary Clinton was the initiator of this dangerous approach by spearheading the disastrous nuclear deal. Disregarding the threat of radical Islamic terrorism is par for the course with the Democrat Party, and a Hillary Clinton presidency will only mean more of the corrupt bargaining with rogue regimes which has compromised the security of the United States and our ally Israel.”