Israel said it was "very concerned" after Iran confirmed it had conducted a final test of its Shahab-3 ballistic missile capable of hitting its territory.
"We are very concerned, especially since we know that Iran is seeking to acquire the nuclear weapon," government spokesman Avi Pazner told AFP on Monday.
"We informed our American and European friends of our concern. Everything must be done to prevent Iran from acquiring the nuclear weapon. The combination of the Shahab-3 and the nuclear weapon would be a very serious threat on the stability of the region," he added.
Iran earlier confirmed it had conducted a final test of its Shahab-3, a medium-range ballistic missile that has a range of 1,300 kilometres (810 miles) and can reportedly carry a warhead of between 700 and 1,000 kilograms (2,222 pounds).
Israel warned against the "Iranian threat" in May 2002, following a previous test of the Shahab-3 missile.
In May, Israeli Foreign Minister Silvan Shalom warned that Iran could possess weapons of mass destruction by 2006.
According to the Israeli daily Haaretz, the issue is due to be discussed by Israeli chief of staff Moshe Yaalon during a visit to Washington this week.
"The latest tests of the Shahab-3 confirm the concerns Israel had over the development of Iran's ballistic arsenal and fears over its intentions," Israeli analyst Mark Heller told AFP.
"The real danger lies in the development of its nuclear program and Israel relies mainly on the United States to deal with this threat," said Heller, from the Jaffee Center for Strategic Studies in Tel Aviv.
"The Iranian test is worrying because it proves that Iran is developing missiles capable of firing arms of mass destruction on distant targets," analyst Shai Feldman said.
Both commentators nevertheless ruled out the possibility of a pre-emptive Israeli strike on Iran's nuclear facilities, such as Israel's 1981 air raid against the Iraqi nuclear plant of Osirak.
"The operational conditions are not the same. Iran has learnt lessons from Osirak. Its nuclear facilities, such as missile-launchers, are buried deep inside Iranian territory and scattered over a wide area," Heller pointed out.
"The geostrategic situation in the region has completely changed, with the presence of US troops in Iraq (news - web sites). And the international community is more concerned with the Iranian nuclear threat than it was with the Iraqi program," Feldman explained.
Since Saddam Hussein's regime fell on April 9, Iran -- which in 2002 US President George W. Bush (news - web sites) described as forming part of an "axis of evil" together with Iraq and North Korea (news - web sites) -- has become the Jewish state's enemy number one.
Israel broke diplomatic relations with Iran in 1979 after the fall of the Shah and the creation of the Islamic republic, which it accuses of supporting anti-Israeli terrorism.
In January 2002, the Israeli navy intercepted a ship carrying 50 tonnes of arms, which the Jewish state charged were sent by Iran to Palestinian militant organisations.
Tehran is accused of financing the Lebanon-based Shiite militia Hezbollah, as well as several radical Palestinian groups, such as Hamas and Islamic Jihad.
Despite breaking off diplomatic relations with Iran after the collapse of the Shah's regime, Israel has nevertheless maintained shadowy relations with the Islamic Republic, supplying it with arms during its 1980-1988 war with Iraq.