Trump railed against the agreement while still on the campaign trail, calling it “the worst deal ever negotiated.” The nuclear deal, formally known as the JCPOA, lifted sanctions on Iran in exchange for a stop to its nuclear program. Still, Trump has allowed the deal to stay in place, but it seeking information to determine if Iran has violated its terms.

To that end, Haley is visiting the IAEA. She will meet with IAEA Director General Yukiya Amano, and some of the technical experts who monitor nuclear activities, including those in Iran governed by the nuclear pact signed by the U.S., and a handful of its allies, as well as Russia and Iran.

However, Iran’s foreign minister wrote a letter to nuclear inspectors warning them not to share any information with Haley that the United States is not entitled to under the deal.

As was reported by the Washington Examiner, Foreign Minister Mohammad Javad Zarif said Haley and the United States were “openly hostile to the (deal) and determined to undermine and destroy it.”

Haley claims that she only wants to question IAEA officials, and criticized Iranian efforts to block nuclear inspectors from visiting certain sites. “Why would they say that if they had nothing to hide? Why wouldn’t they let the IAEA go there?” Haley told Reuters. She also said, ”If you look … at past Iranian behavior, what you’ve seen is there have been covert actions at military sites, at universities, things like that.”

Her trip comes in the midst of the Trump administration’s war of words with Iran. Recently, Iran’s nuclear chief, Ali Akbar Salehi, issued an ominous warning that Iran could, “if we make the determination… resume 20 percent-enrichment in, at most five days.” Under the terms of the nuclear deal, that level of enrichment can make it useable in nuclear weapons, and Iran is banned from doing so.

Haley stated that International inspectors “have the authority to look at military sites now. They have the authority to look at any suspicious sites now,” but asked, “It’s just, are they doing it?”