"The struggle against the leaders of the Iranian regime is more important than [the struggle against] the bombs," Peres said, speaking at the Jewish Agency assembly in Jerusalem.
The president also attacked Iran's Supreme Leader Ayatollah Ali Khamenei, who has hinted that Israel and the US were behind the pro-Mousavi riots in Teheran.
"How dare he claim that we demanded that the Iranian people head to the streets and risk their lives?" Army Radio quoted Peres as saying.
Also Sunday, Iran's Parliament reiterated warnings sounded by Khamenei in which he said that leaders of the US, UK, France and Germany must not to interfere in the country's internal affairs, threatening that Iran would respond to such meddling "in other fields."
Iranian parliament speaker Ali Larijani directed a message at US President Barack Obama, saying that he "showed the deceitful meaning of change too soon."
According to Iran's ISNA news agency, Larijani called for the National Security and Foreign Policy Commission of the Iranian Parliament to revise relations with the US, UK, France and Germany.
In his speech Friday, Khamenei blamed the United States, Britain and "other enemies" for fomenting unrest. He said Iran would not see a second revolution like those which transformed the countries of the former Soviet Union.
"These divisions come from the Zionist radio and the bad British radio trying to change the meaning of the election," Khamenei said.
He said the election outcome was a vindication of the Islamic republic and an earthquake for its enemies. "If the people did not trust in the system they would not participate in it," he said. "Iran's enemies are targeting the beliefs and trust of the people."