As President Donald Trump’s nominee for treasury secretary continues to wait for Senate confirmation, an architect of the Obama administration’s Iran nuclear deal is currently running the agency.

“Once Iran came to the table, we reached a strong, comprehensive deal,” Adam Szubin says.

Acting Treasury Secretary Adam Szubin—who had been a career department employee—previously served as the acting undersecretary for terrorism and financial crimes in the Obama administration. The Senate never confirmed Szubin.

A White House spokesman told The Daily Signal this week there are no announcements planned as to whether Szubin will remain in the Treasury Department after Trump’s nominee, Steven Mnuchin, is confirmed as treasury secretary. Mnuchin is expected to get a Senate vote Saturday.

Since Jan. 20, and until Mnuchin is confirmed, Szubin is running the agency. It’s the same type of role that Sally Yates had at the Department of Justice before she was fired Jan. 30 for refusing to defend Trump’s immigration executive order.

The Treasury Department is charged with implementing the Trump administration’s new Iran sanctions. White House press secretary Sean Spicer told The Daily Signal during a press briefing this week those sanctions were applied and “went off without a hitch.”

The Trump administration last week announced new economic sanctions on 13 Iranian individuals and 12 Iranian companies in response to the country’s missile test in support of Houthi rebels in Yemen. The sanctions do not affect the Obama administration’s negotiated multilateral nuclear deal with Iran, known as the Joint Comprehensive Plan of Action.

The Treasury Department did not respond to questions from The Daily Signal.

Keeping former Obama administration officials on board could threaten the effectiveness of the new sanctions, said Fred Fleitz, a former chief of staff for arms control and international security at the State Department, working under then-undersecretary John Bolton.

“I would be concerned about implementation and enforcement of Iran sanctions with Obama holdovers in place,” Fleitz, now the senior vice president for policy and programs at the Center for Security Policy, a national security think tank, told The Daily Signal in a phone interview. “Having a confirmed treasury secretary in fast should be a priority.”

Fleitz said he is more concerned with State Department officials in the arms control bureaus, who are hostile to Trump and strongly support the Joint Comprehensive Plan of Action, being in charge of the deal.

Szubin’s time is limited at this point, and it could be too early to pre-judge what he will do, said Mark Dubowitz, a CEO of the Foundation for Defense of Democracies, a national security think tank.

“Adam Szubin is a strong believer in the Iran deal, but he is a consummate professional who is extraordinarily talented at finding innovative ways to squeeze the Iranian regime. But he is leaving soon,” Dubowitz told The Daily Signal in an email.

The Wall Street Journal reported last month that Trump chose to keep Szubin at the Treasury Department for now to maintain continuity, but that report regarded his acting undersecretary role. It could also be a sign of the new administration’s policy, said Jim Phillips, senior research fellow for Middle Eastern affairs at The Heritage Foundation.

“I think it is one more sign that the Trump administration is in no hurry to tear up the deal and is still reviewing its options,” Phillips told The Daily Signal in an email.

Szubin’s job as acting undersecretary for terrorism and financial intelligence was to disrupt financial support to international terrorist organizations, proliferators of weapons of mass destruction, and narcotics traffickers. President Barack Obama nominated Szubin to this political position in 2015 in an acting role, though the Senate never confirmed him.

Before the Iran deal, Szubin also helped to draft tough sanctions against Iran, which he later said helped force the country to negotiate.

Speaking at the Atlantic Council and the Iran Project Symposium on Dec. 17, 2015, Szubin said:

Our sanctions worked as intended. Iran would not have come to the table as seriously as it did were it not for the powerful array of sanctions robustly enforced by the U.S. and our allies around the world. And once Iran came to the table, we reached a strong, comprehensive deal that closes every pathway to an Iranian nuclear weapon.

While serving as acting undersecretary in the summer of 2015, Szubin traveled to Israel to lobby government officials to support the Iran nuclear deal, Foreign Policy reported.

Sen. Tom Cotton, R-Ark., blocked the Szubin nomination for undersecretary from coming to the Senate floor last year. He said Szubin is “well respected on both sides of the aisle,” but his key objection was to the Iran policy pushed by Obama, Secretary of State John Kerry, and Treasury Secretary Jack Lew.

“Until President Obama, and Secretary Kerry, and Secretary Lew publicly and conclusively renounce any intent to allow Iran to dollarize a foreign transaction, I will object to this nomination,” Cotton said, according to The Hill.

Cotton’s office did not respond to inquiries from The Daily Signal for this story.

Szubin began working in the Treasury Department under President George W. Bush as a career employee, serving as director of the department’s Office of Foreign Assets Control, a position he held from 2006 to 2015. Before that, Szubin worked in the Justice Department. From 1999 to 2000 he clerked for Judge Ronald Gilman, a President Bill Clinton appointee on the U.S. Court of Appeals for the 6th Circuit.