Yuval Steinitz, Israel's minister of intelligence and strategic affairs, issued the call on Sunday. He spoke a day after Iran and six world powers failed to agree at talks in Kazakhstan on how to reduce fears Tehran might use its technology to make weapons.
"The time has come to present the Iranians with a military threat or some kind of red line or unequivocal ultimatum by the entire world ... in order to get results," Steinitz told Army Radio.
He said the ultimatum should be "weeks," without elaborating. Israel and the US have hinted at a military option if diplomacy fails.
Israel believes Iran is developing a nuclear bomb. Iran denies the charge.