On Wednesday, House Foreign Relations Committee chairman Ed Royce (R-CA) sent a letter to Secretary of State John Kerry, containing a list of questions about the $1.7 billion payment made to Iran.

As Fox News notes, the Administration has described the payment as settlement for a dispute over frozen Iranian assets going back to 1979, while critics view it as more akin to a “ransom payment” for the American hostages released last month.

Royce wrote that it was “unclear how this $1.7 billion payment is in the national security interests of the United States.”

Critics of the payment were incensed to learn that most of it – $1.3 billion out of the $1.7 billion total – was considered to be “interest” backdating to 1979. Royce asked how the interest amount was calculated.

The President has insisted that the payment was “much less than the amount Iran sought,” and warned further interest would have accumulated while awaiting a judgment from the Iran-U.S. Claims Tribunal, which has somehow been working on that judgment since 1981 without results.

He also asked Kerry for a timeline of the negotiations, a list of the U.S. officials who participated, a legal analysis of the dispute that was settled, a list of other claims still outstanding before the Claims Tribunal, and why the hefty sum was not used to “compensate American victims of Iranian terrorism who have been awarded judgments against Iran.”

According to Reuters, Royce’s letter mentioned the ransom complaint, saying that the timing of the settlement combined with the Administration’s failure to brief Congress “has led some to express concern that the payment represents a de facto ‘ransom’ for the release of American hostages.”

Some Iranians have not been shy about describing the huge payment as a ransom, including Brigadier General Mohammed Reza Naqdi, commander of the Basij Force, who said the money was payment for the “freedom of a U.S. spy” and crowed that Obama’s capitulation “showed that the U.S. doesn’t understand anything but the language of force.”

Royce said he has a “larger concern” that the $1.7 billion payoff for a “relatively minor bilateral dispute” was part of an Administration strategy of “aggressively moving towards reestablishing diplomatic relations with Iran.” Restoring such diplomatic relations, which broke off after the 1979 hostage crisis, is not part of the President’s Iranian nuclear deal.

“The [State] Department had ample opportunity to seek Congressional input on this matter,” Royce charged in the letter to Kerry. “Yet, it never raised this potential financial settlement with the Committee.”

The Washington Post notes that “lawmakers from both parties have raised concerns about whether the Administration is aggressively holding Tehran accountable for objectionable activities outside the parameters of the nuclear deal, including recent ballistic missile tests.”

Royce expressed such doubts in his letter, wondering about the Obama Administration’s commitment to “countering the threat Iran poses to the United States and our allies in the region.”

The Washington Post notes that Royce sent his letter to Kerry after the Administration “did not respond to earlier inquiries,” and that Royce’s committee plans to hold Iran hearings next Thursday.