ANKARA (Reuters) – Iran has dismissed a U.S. demand for U.N. nuclear inspectors to visit its military bases as “merely a dream” as Washington reviews a 2015 nuclear agreement between Tehran and six world powers, including the United States.

U.S. President Donald Trump has called the nuclear pact – negotiated under his predecessor Barack Obama – “the worst deal ever”. In April, he ordered a review of whether a suspension of nuclear sanctions on Iran was in the U.S. interest.

The U.S. ambassador to the United Nations, Nikki Haley, last week pressed the International Atomic Energy Agency (IAEA) to seek access to Iranian military bases to ensure that they were not concealing activities banned by the nuclear deal.

“Iran’s military sites are off limits… All information about these sites are classified,” Iranian government spokesman Mohammad Baqer Nobakht told a weekly news conference broadcast on state television. “Iran will never allow such visits. Don’t pay attention to such remarks that are only a dream.”

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.

Under terms of the deal, the international nuclear watchdog can demand inspections of Iranian installations if it has concerns about nuclear materials or activities.

During its decade-long stand-off with world powers over its nuclear program, Iran repeatedly rejected visits by U.N. inspectors to its military sites, saying they had nothing to do with nuclear activity and so were beyond the IAEA’s purview.

Iran has placed its military bases off limits also because of what it calls the risk that IAEA findings could find their way to the intelligence services of its U.S. or Israeli foes.