"I believe more than 75% (of the people) there would have liked to replace the regime, and that percentage has recently risen," he told reporters after a meeting with Italian Prime Minister Silvio Berlusconi.
"This is a regime that needs to be condemned, as I said to Berlusconi, and if not today then when? We need to put pressure on it," he added.
President Shimon Peres joined the onslaught Tuesday, characterizing the Iranian regime as "pathetic and rotten."
"This regime is cracked and full of wounds, and enriched uranium cannot fill that void," he added.
Speaking at the Israel Defense Prize award ceremony, held at his official residence in Jerusalem, Peres said, "In elections in a democratic regime, the vote determines who wins, and in an undemocratic regime, the count determines who wins."
Defense Minister Ehud Barak, also present at the ceremony, said Israel stood before a danger faced by no other country. "Regarding Iran, Hizbullah, Hamas, and other terror organizations, we are witnessing some fascinating developments in our region that require us to be prepared and alert," he said.
Britain expels Iranian diplomats
Meanwhile, Britain expelled two Iranian diplomats Tuesday in retaliation for Iran's decision to order out two staff members from the British Embassy in Tehran.
"Iran yesterday took the unjustified step of expelling two British diplomats over allegations which are absolutely without foundation," Brown told parliament.
"In response to that action, we informed the Iranian ambassador today that we would expel two Iranian diplomats from their embassy in London," he added.
"I am disappointed that Iran has placed us in this position, but we will continue to seek good relations with Iran and to call for the regime to respect the human rights and democratic freedoms of the Iranian people," Brown said.
The Foreign Office said Iran was seeking to blame the UK and other outsiders for what is an Iranian reaction to an Iranian issue.
Iran's rulers have firmly rejected the demands of protesters to annul the recent election over fraud allegations, and have kept troops in riot gear on the streets to break up any gatherings.
Iran informed the British government on Monday that it was expelling two diplomats whom it accused of "engaging in activities incompatible with diplomatic duties" – a euphemism for spying.
Iran's ambassador to London was called to a meeting at the Foreign Office and was told the allegation was unjustified, a Foreign Office spokesman said.
Aviad Glickman and AP contributed to this report