Rafael Mariano Grossi, director general of the International Atomic Energy Agency, has shared his concerns about the Iran-Israel conflict with the agency’s board of directors.

“Military escalation threatens lives, increases the chance of a radiological release with serious consequences for people and the environment and delays indispensable work towards a diplomatic solution for the long-term assurance that Iran does not acquire a nuclear weapon,” Grossi said on June 16. “Consistent with the objectives of the IAEA and its statute, I call on all parties to exercise maximum restraint to avoid further escalation.”

U.S. and Israeli officials are now confirming that an October 25 Israeli attack in Iran destroyed an active top secret facility for nuclear weapons research, Axios reports. The strike is said to have significantly hampered efforts by Iran to resume weapons research, despite ongoing denials from the country’s leaders that there is an active weapons program.