The U.N. atomic watchdog declined on Tuesday to directly address Israeli Prime Minister Benjamin Netanyahu's accusations that Iran was breaching its landmark nuclear deal with major powers.

Netanyahu on Monday stepped up pressure on the United States to pull out of the 2015 deal, presenting what he called evidence of a secret Iranian nuclear weapons programme.

Iran is known to have had a weapons programme until 2003, and analysts and diplomats said he appeared to be recycling old accusations.

"In line with standard IAEA practice, the IAEA evaluates all safeguards-relevant information available to it," an International Atomic Energy Agency spokesman said.

"However, it is not the practice of the IAEA to publicly discuss issues related to any such information."