Iran has warned Israel it will react "most severely" if Israel uses force to try to destroy its nuclear facilities.
Iran now expects to start up its first nuclear reactor in 2006
Foreign Minister Kamal Kharrazi was
responding to reports that the United States is to sell Israel hundreds of "bunker-busting" bombs.
Israel urged the United Nations Security Council to take action to stop Iran's nuclear programme.
The US and Israel have accused Iran of seeking to develop nuclear weapons, a charge Iran denies.
Iran recently defied calls by the UN's nuclear watchdog to suspend all enrichment-related activities, insisting its nuclear programme was for peaceful purposes only.
According to reports, the US is to sell Israel 5,000 hi-tech bombs, including 500 one-ton "bunker-busters", which can penetrate two metre (6.5ft) thick walls.
In 1981, Israel bombed Iraq's Osirak nuclear reactor when it believed Saddam Hussein was close to producing a nuclear bomb.
Israeli Foreign Minister Silvan Shalom said the UN must deal with the threat of Iranian nuclear weapons before it is too late.
"[The Iranians] are trying to buy time, and the time has come to move the Iranian case to the Security Council in order to put an end to this nightmare," he told reporters after meeting UN Secretary General Kofi Annan.
"We know that the Europeans are trying now to engage with the Iranians, but we know that the Iranians will never abandon their plans to develop nuclear weapons. They're only trying to hide it."
However, Kamal Kharrazi said Israel, not Iran, was a threat to world peace.
"Israel has always been a threat, not only against Iran, but all countries."
When questioned about Israel's reported purchase of the bombs, Mr Kharrazi said, "be sure that any action by Israel certainly will be reacted by us most severely".