Israel's prime minister has urged the international community to get tougher against Iran, saying that without a "clear red line," Tehran will not halt its nuclear programme.
The tough language from Prime Minister Benjamin Netanyahu reflected differences that have emerged between Israel and its allies, particularly the US, over how to deal with Iran.
Israel has warned that the Iranians are quickly approaching weapons capability and that the threat of force must be seriously considered. The US says sanctions and international diplomacy must be given more time to work.
Netanyahu, speaking to his Cabinet, said that a new report issued by the UN nuclear agency showing progress in the Iranian nuclear programme bolstered his claim that international pressure is not working.
"I believe that the truth must be said, the international community is not drawing a clear red line for Iran, and Iran does not see international determination to stop its nuclear programme," Netanyahu said.
"Until Iran sees this clear red line and this determination, it will not stop its advancement of the Iranian nuclear programme. Iran must not have a nuclear weapon," he declared.
Iran says its nuclear programme is for peaceful purposes only, a claim that is rejected by the West. Israel believes a nuclear-armed Iran would pose a mortal threat, citing Iranian calls for Israel's destruction, its development of missiles capable of striking Israel and its support for anti-Israel militant groups.
Israeli leaders have repeatedly hinted they are growing impatient and could soon be compelled to use force against Iran. The United States opposes a unilateral Israeli strike.
The strain between Washington and its long-time Israeli ally has been on full display in recent weeks, with the US military chief, Gen Martin Dempsey, twice speaking out against a go-it-alone strike. Last week he said he would "not want to be complicit" in such an assault.
Washington worries that a premature Israeli attack could send global oil prices soaring and touch off a broad conflict possibly drawing in US forces just as the US is preparing to hold presidential elections.