UNITED NATIONS (Reuters) - U.S. Ambassador to the United Nations Nikki Haley on Friday pressed the International Atomic Energy Agency to seek access to Iranian military bases to ensure that they are not concealing activities banned by the 2015 nuclear deal.

“I have good confidence in the IAEA, but they are dealing with a country that has a clear history of lying and pursuing covert nuclear programs,” Haley told a news conference after returning from a trip to the Vienna-based U.N. agency.

“We are encouraging the IAEA to use all the authorities they have and to pursue every angle possible” to verify compliance with the nuclear deal, she said.

Haley visited the U.N. nuclear watchdog’s headquarters as part of U.S. President Donald Trump’s review of the Iran nuclear deal, known as the Joint Comprehensive Plan of Action (JCPOA), made by former President Barack Obama.

The deal is designed to prevent Iran from developing nuclear weapons by imposing constraints on its nuclear program in return for the lifting of international sanctions on Tehran. The IAEA concluded that Iran secretly researched a nuclear warhead until 2009, which Tehran denies.

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.

“The JCPOA made no distinction between military and non-military sites. There are also numerous undeclared sites that have not been inspected. That is a problem,” said Haley.

Iran is suspected by the IAEA of conducting weapons-related activities at at least one military site years before the 2015 deal.

Daryl Kimball, executive director of the Arms Control Association, a think tank, said that the deal sets out a process for the IAEA to request access to any Iranian site, and that it would be publicly known if such a request was made and rejected.

“The agency to our knowledge has not requested access to any site and been denied,” he said. “Furthermore, the agency cannot and should not seek access to a site simply to test the Iranians’ cooperation. They must have a legitimate reason.”

Kimball charged that the Trump administration “is seeking a pretext” to accuse Iran of not complying with the deal, which Trump has repeatedly vowed to tear up.

Haley also leveled harsh criticism at Irish Major General Michael Beary, the commander of United Nations forces in Lebanon, accusing him of turning a blind eye to Iran’s covert arming of the Hezbollah militant group.

“General Beary says there are no Hezbollah weapons,” she said. “That’s an embarrassing lack of understanding on what’s going on around him,” she said.