A UN atomic watchdog's report saying that Iran has substantially boosted uranium enrichment is "added proof" that Tehran is trying to obtain nuclear weapons, Israel said.
"The report by the International Atomic Energy Agency gives added proof that Israeli beliefs are true" about Iran's nuclear programme, a statement from Prime Minister Benjamin Netanyahu's office said.
"Iran is pursuing its nuclear programme with no end in sight. It is enriching uranium to 20 percent, totally ignoring demands by the international community" to stop its activities, it said.
The IAEA said in a report on Friday that Iran had tripled its capacity to enrich uranium to 20-percent purity since November, and was now producing around 14 kilos of uranium per month, with around 105 kilos already stockpiled.
Enriching uranium to 20 percent is a major step towards purifying it to the 90-percent level needed for a nuclear weapon, although Iran denies intending to do so, saying its atomic activities are entirely peaceful.
"An intensive discussion was held on the structured approach to the clarification of all outstanding issues related to Iran's nuclear programme" during two recent visits, the IAEA said in a report circulated to member states.
"No agreement was reached between Iran and the Agency, as major differences existed," it said in the report seen by AFP.
"The agency continues to have serious concerns regarding possible military dimensions to Iran's nuclear programme," the IAEA said in the report two days after a team returned from Tehran.
Israelis coming under increased pressure from Washington and Europe to hold off from attacking Iran over its disputed nuclear drive.
US intelligence analysts believe there is no hard evidence that Iran has decided to build a nuclear bomb, The New York Times reported on Saturday.
Citing unnamed US officials, the newspaper said the latest assessments by US spy agencies are broadly consistent with a 2007 intelligence finding that concluded that Iran had abandoned its nuclear weapons programme.
Israeli President Shimon Peres warned on Thursday that Israel was keeping "all options" on the table.
"The state of Israel is a sovereign state; it has the right and capacity to defend (itself) against any threat," he said.
"When we say that all options are on the table, we really mean it," Peres added.