Secretary of State John Kerry and Iranian Foreign Minister Javad Zarif, who led the U.S. and Iranian nuclear negotiating teams, stroll in Geneva on January 14, 2015. (AP Photo/Keystone, Laurent Gillieron, File)

(CNSNews.com) – Sen. Tom Cotton (R-Ark.) on Wednesday likened the manner in which the Obama administration paid $400 million to Iran on the day five imprisoned Americans were released to a “drug cartel transaction.”

Speaking to Fox News’ Greta Van Susteren, Cotton described the incident last January as “$400 million in small unmarked bills, flying into Iran on a unmarked aircraft, like it was a drug cartel transaction, not a legitimate negotiation between two governments.”

The administration maintains that the $400 million it paid to Iran was settlement of an unresolved claim dating back to the 1979 Islamic revolution, plus an agreed $1.3 billion in interest.

It has consistently denied that the payment amounted to a “ransom” for the Americans, or indeed was linked in any way to their release – or to the simultaneous implementation of the nuclear deal struck with Iran in drawn-out multilateral negotiations.

Although the administration made no secret of the settlement payout at the time, it did not disclose how the transaction took place. The Wall Street Journal reported this week that foreign currency banknotes to the equivalent of $400 million were packed on a pallet and flown to Tehran in an unmarked aircraft.

Cotton, a longstanding critic of the nuclear deal, said the U.S. would be unable to trace the “cold, hard cash” or determine what it’s being used for. But he recalled that even White House press secretary Josh Earnest has acknowledged that Iran could use the money it has to sponsor terrorism.

(Earnest said during a daily press briefing Wednesday the administration knows “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.”)

Beyond criticizing the way the money was sent to Iran, Cotton also rejected the denials that the money was linked to the prisoners’ release, calling the timing “highly suspect.”

He pointed out that the legal claim, which related to an unfulfilled weapons supply agreement with Iran’s pre-revolutionary government, had been disputed for 36 years.

Then “just miraculously, on the day that hostages were released and the Iran nuclear deal was implemented, they finally resolve that dispute.”

Cotton doubled down on his and others’ earlier criticism of the administration for agreeing to negotiate with Iranians over the nuclear issue in the first place before Americans they were holding were freed.

“We should have said very clearly that we wouldn’t even talk to Iran about its nuclear program until all Americans held in captivity were released,” he said.

He recalled that when the talks began four years ago Iran’s economy was suffering as a result of sanctions, thus giving the U.S. leverage. (Cotton noted as an aside that tough sanctions were imposed by Congress in the face of resistance by President Obama and then-Secretary of State Hillary Clinton.)

“The sanctions were tough enough that we could set the terms of the negotiations, which included releasing all American hostages before we even sat down,” he said.

“Now what do we have? A bad deal, and more Americans being held hostage – and Iran with $400 million in cold hard cash.”

Citing the still-missing former FBI agent Bob Levinson, who disappeared in Iran in 2007, and the fact other Americans are now being held in Iran, Cotton called the episode “just one more chapter in the very sad, long history of Barack Obama’s feckless dealings with the ayatollahs in Iran.”

‘Creative’

The White House and State Department both pushed back Wednesday against criticism arising from the Wall Street Journal report.

Earnest at the White House characterized the critics as “those who are flailing in an attempt to justify their continued opposition to the deal to prevent Iran from obtaining a nuclear weapon.”

State Department spokesman Mark Toner, asked whether flying in banknotes stacked on a pallet in an unmarked plane was “typically how we do business,” said he was not going to confirm the “allegations” about the manner in which payment was made.

But his next words came close to doing just that.

“What I will say is that when we’re forced to get a little creative – let me put it this way – when we’re dealing with a country that was largely cut off from international financial institutions and the international banking system due to years of sanctions, and so operating in that environment we had to look at available options to us in order to get that money to them.”

And when asked whether a cash transaction was “unseemly,” he described it as “the most efficient way to do it.”

As for the persisting ransom accusation, Toner said, “there was no linkage between the settlement and the freeing of these Americans.”

“There was not any kind of understanding on the part of the Iranians, and certainly not on the part of us, that these two [issues] were linked, that one had to happen before the other would,” he said.

Toner described the nuclear deal implementation, the prisoner release, and the settlement payout as three “separate but distinct lines of effort, operating concurrently.”

The Americans released by Iran that day were Pastor Saeed Abedini, a convert from Islam who was serving an eight-year prison term for “crimes against national security”; Washington Post reporter Jason Rezaian and former U.S. Marine Amir Hekmati, both convicted of espionage and in the latter case at one stage sentenced to death; researcher Matthew Trevithick; and an Iranian-American named as Nosratollah Khosravi-Roodsari.