UNITED NATIONS (Reuters) - The United States wants to know if the United Nations atomic watchdog plans to inspect Iranian military sites to verify Tehran’s compliance with a 2015 nuclear deal, the U.S. ambassador to the United Nations, Nikki Haley, said on Tuesday.

FILE PHOTO: U.S. Ambassador to the United Nations Nikki Haley testifies to the House Foreign Affairs Committee on "Advancing U.S. Interests at the United Nations" in Washington, U.S., June 28, 2017. REUTERS/Joshua Roberts/File Photo

Haley met International Atomic Energy Agency (IAEA) officials in Vienna on Wednesday for what she described as a fact-finding mission, which is part of President Donald Trump’s review of the deal Iran made with world powers to curb its nuclear program in return for the lifting of most sanctions.

“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,” Haley, a member of Trump’s cabinet, told Reuters in an interview.

“There were already issues in those locations, so are they including that in what they look at to make sure that those issues no longer remain?” she said. “They have the authority to look at military sites now. They have the authority to look at any suspicious sites now. It’s just are they doing it?”

She said she was traveling to Vienna to ask questions, not to push the IAEA to do anything.

According to the 2015 deal, also known as the Joint Comprehensive Plan of Action (JCPOA), requests for access “will not be aimed at interfering with Iranian military or other national security activities.”

If the IAEA has concerns about “undeclared nuclear materials or activities, or activities inconsistent with the JCPOA, at locations that have not been declared” under Iran’s safeguards agreements, the deal requires the agency to provide Iran the basis for such concerns and request clarification.

If Iran’s proposals to resolve such concerns are not deemed satisfactory, there is a mechanism in which a majority of the parties to the deal can force Iran to “implement the necessary means” within three days.

When asked about Haley’s visit, a spokesman for the IAEA said it had no immediate comment.

Iran’s top authorities have rejected giving international inspectors access to their military sites and officials have told Reuters any such move would trigger harsh consequences.

“Why would they say that if they had nothing to hide? Why wouldn’t they let the IAEA go there?” Haley said.

Iran’s atomic chief was quoted by state media as saying on Tuesday that Iran could resume production of highly enriched uranium within five days if the nuclear deal was revoked.

In April, Trump ordered a review of whether a suspension of sanctions on Iran related to the nuclear deal - negotiated under President Barack Obama - was in the U.S. national security interest. He has called it “the worst deal ever negotiated.”

“WITHIN HOURS”

Iranian President Hassan Rouhani warned last week that Iran could abandon the nuclear agreement “within hours” if the United States imposes any more new sanctions.

The IAEA closed its 12-year investigation into whether Iran had a secret nuclear weapons program in December 2015 after producing a report that strongly suggested Iran did have such a program until 2003.

Most U.N. and Western sanctions were lifted 18 months ago under the nuclear deal. Iran is still subject to a U.N. arms embargo and other restrictions, which are not technically part of the deal.

The IAEA polices restrictions the deal placed on Iran’s nuclear activities and reports quarterly.

Haley said some of the questions she had were: “Are you looking at everything? Are you looking at those places where there has been covert activity in the past? Are you able to get access to these areas? Or are you being delayed? Are you being shut out from those things?”

Under U.S. law, the State Department must notify Congress every 90 days of Iran’s compliance with the nuclear deal. The next deadline is October, and Trump has said he thinks by then the United States will declare Iran to be non-compliant.

“We don’t know if he’s going to certify or decertify the deal,” said Haley, adding that she would report back to Trump and the national security team.

In a statement following the meeting, Haley’s office praised the professionalism and expertise of the IAEA’s work in Iran.

The U.S. review of its policy toward Iran is also looking at Tehran’s behavior in the Middle East, which Washington has said undermines U.S. interests in Syria, Iraq, Yemen and Lebanon.

U.N. Secretary-General Antonio Guterres believes the Iran nuclear deal is “one of the most important diplomatic achievements in our search for ... peace and stability,” U.N. spokesman Stephane Dujarric said on Tuesday.