In an interview with Israel Radio, Deputy Prime Minister Moshe Yaalon said technical problems had prevented Tehran from reaching the goal so far.
Yaalon also said a Hamas takeover in the West Bank is feared by Jordan and Egypt as well as Israel, The Jerusalem Post reported.
Despite recent rocket attacks from the Gaza Strip, Yaalon said a major conflict is unlikely because Hamas does not want to risk a response like the war two years ago, called Operation Cast Lead in Israel.
On Monday, Lt.-Gen. Gabi Ashkenazi, chief of the general staff, warned Israel "will not accept" rocket and mortar fire from Gaza and is ready to respond.
"Two years after Operation Cast Lead, the situation in the Gaza Strip is different and calmer. Yet, sadly, from time to time, rockets and mortar shells are fired at the Israeli home front," he said.