White House Press Secretary Sean Spicer would not say Wednesday whether President Donald Trump will follow through with his criticisms of the Iran nuclear deal or back out of it, after Secretary of State Rex Tillerson announced late Tuesday the administration is launching a review to determine whether suspending Iran sanctions is “vital to the national security interests of the United States.”

Spicer said the interagency review, led by the National Security Council, will evaluate both whether Iran is in compliance with the deal — Tillerson said it is — and make recommendations to the president on what to do next. Asked if Mr. Trump has made a decision on whether to keep the deal, Spicer told reporters in the daily briefing, “that’s why he’s doing a review.”

Mr. Trump, who considers himself a state-of-the-art dealmaker, dubbed the 2015 agreement “the worst deal ever negotiated” during his presidential campaign, raising the questions of whether he might kill the deal deal entirely.

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Tillerson told Speaker of the House Paul Ryan in a letter that Iran is complying with the Obama-era agreement to freeze its nuclear program in exchange for sanctions relief, but warned that, “Iran remains a leading state sponsor of terror through many methods and platforms.” Tillerson said the administration “looks forward” to working with Congress once the review of the Joint Comprehensive Action Plan is complete.

The U.S. top diplomat offered no timeline for that review.

The State Department is required to update Congress on Iran’s compliance with that deal every 90 days. This was the State Department’s first update under Mr. Trump.

The agreement between Iran and six other nations restrict’s Tehran’s nuclear program in exchange for the lifting of international oil and financial sanctions. The deal’s opponents claimed the deal only delayed Iran’s pursuit of nuclear weapons, and that it did not permit full inspections to guarantee Iran wasn’t cutting corners.