VIENNA (AP) — Iran’s nuclear chief said Monday that “terrorists and saboteurs” might have infiltrated the International Atomic Energy Agency in an effort to derail his nation’s atomic program. It was Tehran’s harshest attack on the integrity of the U.N. organization and its investigation of allegations that Iran is striving to make nuclear arms.

Fereydoun Abbasi also rebuked the United States in comments to the IAEA’s 155-nation general conference, reflecting Iran’s determination to continue defying international pressure aimed at curbing its nuclear program and nudging it toward cooperation with the IAEA inspection.