After saying last week that President Barack Obama was “acting like the drug dealer in chief” for the administration’s $400 million cash payment to Iran that coincided with the release of four American prisoners, Illinois Republican Sen. Mark S. Kirk announced that a panel he chairs will hold a hearing on the matter in September. 

Kirk chairs the Senate Banking Subcommittee on National Security and International Trade and Finance, which has oversight of Iran sanctions and terrorist financing. 

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The announcement comes after the Obama administration acknowledged that the payment was used as leverage to ensure Iran would release four U.S. citizens it had been holding hostage. 

The administration had initially tried to downplay the identical January 17 timing of the $400 million payment — reportedly owed to Iran from a 1970s military equipment deal — and Iran’s release of the four Americans.

State Department spokesman John Kirby told The Associated Press on Thursday that although negotiations over the payment were separate from those to free the prisoners, the United States withheld delivery of the money until the Americans were released as leverage. 

“We had concerns that Iran may renege on the prisoner release,” Kirby said.

Even before that acknowledgement, Republicans have been criticizing the administration for making what they see as a hostage payment to Iran. 

[GOP Lawmakers See ‘Ransom’ to Iran Amid White House Denials]

“We can’t have the president of the United States acting like the drug dealer in chief,” Kirk told the editorial board of The State Journal-Register of Springfield on Tuesday, according to a Chicago Tribune report.

By “giving clean packs of money” to Iran, the administration is enabling a “state sponsor of terror,” the senator added. “Those 500-euro notes will pop up across the Middle East. … We’re going to see problems in multiple (countries) because of that money given to them.”

In his statement announcing the September hearing, Kirk suggested that those problems could come from the “Shi’ite Liberation Army” formed by Iran’s Islamic Revolutionary Guard Corps. “The American people have a right to know if any U.S. taxpayer money sent to Iran is going to finance the new ‘Shi’ite Liberation Army,’ Hezbollah or Hamas terrorists targeting our allies in Israel, or any other Iranian terrorist activities,” he said.