Rouhani, speaking to a group of veterans of the eight-year war with Iraq in the 1980s Tuesday, echoed statements made in March by Supreme Leader of Iran Ayatollah Ali Khamenei, the semi-official Fars News Agency reported.
Rouhani said Iran's resistance during the war with Iraq demonstrated its power.
"[The Israelis] know that if something happens, the people of the Islamic Iran will resist more sincerely, more bravely and more powerfully," Rouhani said.
Khamenei said in March Israel knows if it attacks Iran that Haifa and Tel Aviv will be destroyed.
Israeli Prime Minister Binyamin Netanyahu said this week on CBS' "Face the Nation" Iran is "getting closer and closer to the bomb and they have to be told in no uncertain terms that that will not be allowed to happen."
"But as the prime minister of Israel, I'm determined to do whatever is necessary to defend my country, the one and only Jewish state, from a regime that threatens us with renewed annihilation," he said.