The Obama administration will purchase 32 metric tons of nuclear material from Iran, U.S. officials confirmed, in a move likely to anger critics still reeling after Iran received billions in sanctions relief following the implementation of the nuclear deal in January.

The value of the deal: $8.6 million, The Wall Street Journal reports. State Dept. spokeswoman Elizabeth Trudeau would not rule out whether the U.S. would use taxpayer money for the transaction, saying it was possible Iran could use the cash to fund terrorism. A State Dept. official later told Fox News the transaction could involve U.S. dollars.

Iran sent the heavy water to Oman en route to its final destination: the Oak Ridge National Laboratory in Tennessee. The lab's director, Thom Mason, said workers were converting one research facility there to use heavy water instead of light water.

"It was fortuitous in terms of timing," Mason told the Journal. Scientists say heavy water can be used in the process of making plutonium for nuclear weapons.

“This material is not radioactive and does not present safety concerns. This transaction provides U.S. industry with a critical product while also enabling Iran to sell some of its excess heavy water as contemplated in the [nuclear deal]," Trudeau told Fox News.

Secretary of State John Kerry was set to meet with his Iranian counterpart Javad Zarif in New York City Friday afternoon. A State Dept. delegation is also meeting in Vienna today with Iran and six world powers to discuss the nuclear deal and sign the contract moving the purchase forward.

Earlier this week, in a candid admission, State Dept. spokesman John Kirby said, "we don't know" if $3 billion in sanctions relief given to Iran had gone to fund terrorism operations. The rogue nation has conducted a string of missile tests this year, which U.S. officials say runs afoul of a U.N. Security Council resolution tied to the nuclear deal.

The Dept. of Energy is buying the material in part because U.S. officials are concerned Iran can't effectively cut its stockpile quickly enough, the Journal reports, adding that few other shoppers are stepping up and making an offer.

Critics argue this was part of Iran's plan all along. "Iran has created a clever scheme – produce too much heavy water so as to break the nuclear agreement, then get the Obama administration and eventually US companies to pay Tehran to get rid of it. Rinse, repeat," Foundation for Defense of Democracies Executive Director Mark Dubowitz responded.

Still, the State Dept. argued that Iran did not possess more heavy water than the nuclear deal had allowed. Iran ensured the material "would not be used to support the development of a nuclear weapon. Our purchase of the heavy water means that it will instead be used for critically important research and non-nuclear industrial requirements," Kirby added.

Iran wants financial restrictions that remain eased, or at the very least, clarified. Despite the relief it was given in the nuclear deal, Iran remains under numerous U.S. sanctions related to its ballistic missile activity, support for terrorism and human rights abuses.

The Obama administration insists it has met its obligations under the nuclear deal but acknowledges that some sanctions relief has been slow. The administration has ruled out giving Iran access to the U.S. financial system or direct access to dollars.

Zarif complained this week that the administration has not been "proactive" in explaining the sanctions relief to international banks and that as result, Iran remains locked out of the international financial system. That is disputed by Washington, which notes it has dispatched officials to explain to banks and other businesses what is legal.

Congressional Republicans called on Kerry Thursday to specifically rule out the possibility that Iran will be given even indirect access to either the dollar or the U.S. financial system. They pointed to comments Kerry made after his Tuesday meeting with Zarif in which he said that they would use Friday's meeting to "solidify" efforts to ensure Iran gets what it deserves under the deal.

"The administration should definitively rule out any potential workaround that provides Iran -- directly or indirectly -- with access to the dollar or the U.S. financial system," House Speaker Paul Ryan of Wisconsin said in a statement. "We hope that's the message Secretary Kerry delivers to Foreign Minister Zarif on Friday."

House Majority Leader Rep. Kevin McCarthy, R-Calif., meanwhile, tweeted that "We cannot grant Iran access to the dollar in any form."

Their comments come after House Foreign Affairs Committee Chairman Ed Royce of California introduced a bill that prohibits the administration from allowing the dollar to be used in trade transactions with Iran.

Fox News' Lucas Tomlinson and The Associated Press contributed to this report.