Israeli Prime Minister Benjamin Netanyahu told a visiting US congressman on Friday that Iran was speeding up its quest for nuclear weapons in defiance of international sanctions.
"Just yesterday, we received additional proof of the fact that Iran is continuing to make accelerated progress toward achieving nuclear weapons while totally ignoring international demands," Netanyahu's office quoted him as telling Republican Congressman Mike Rogers.
Netanyahu was referring to a story in Thursday's Washington Post that cited "diplomats and experts" as saying a forthcoming International Atomic Energy Agency (IAEA) report would show Tehran had installed hundreds of new centrifuges "and may also be speeding up production of nuclear fuel."
Netanyahu's comments came as IAEA and Iranian officials met on Friday at the Iranian mission in Vienna to discuss what the agency called "outstanding issues" over Tehran's contested nuclear drive.
Israel and its ally, the United States, accuse Iran of seeking to develop an atomic arsenal but Tehran insists its nuclear programme is only for civilian purposes.
Widely suspected to have the region's sole, if undeclared, nuclear arsenal, Israel has warned that if need be it will attack nuclear facilities in the Islamic republic to prevent it becoming capable of producing nuclear weapons.