“The very existence of the Zionist regime is an insult to humankind and an affront to all world nations,” the news agency’s English-language report on the speech quoted him as saying. “Confronting Zionists will also pave the way for saving the whole humankind from exploitation, depravity and misery.”

In another passage, Mr. Ahmadinejad was quoted as saying that Jerusalem Day, which the Iranians call Quds Day after the city’s Arabic name, was “an occasion for all human communities to wipe out this scarlet letter, meaning the Zionist regime, from the forehead of humanity.”

A violently anti-Israel message was also the theme of Jerusalem Day commemorations in Beirut, Lebanon, the home base of Hezbollah, the militant political organization that fought a war with Israel in 2006 and is aligned with the governments of Iran and Syria in what they call the axis of resistance. Hassan Nasrallah, the Hezbollah secretary general, said in a televised speech that its arsenal of missiles trained on Israel included precision-guided rockets that could transform “the lives of hundreds of thousands of Zionists into hell.”

Israel considers Iran its most dangerous adversary because of Iran’s suspect nuclear program, missiles capable of hitting Israeli targets, and support for militant Palestinian groups on Israel’s borders. Conversely, Iran’s clerical rulers have considered Israel one of the world’s most arrogant and dangerous powers since they came to power in the Islamic revolution of 1979. Iranian officials constantly point out that even though they repudiate nuclear weapons, Israel has an arsenal of them.