"The international community cannot be silent in situations where the violation of human rights is systemic, grave, and widespread, and where states dismiss issues of human rights and refuse to engage in meaningful dialogue," Israel's deputy UN ambassador Daniel Carmon said Friday.
Israel's UN Mission released excerpts from the letters to Secretary-General Ban Ki-moon and General Assembly President Sheikha Haya Rashed Al Khalifa.
It cited Iranian President Mahmoud Ahmadinejad's denial of the Holocaust and his calls for Israel's destruction while developing an ominous military nuclear weapons program.
The Israeli mission said Ahamdinejad's rhetoric constitutes incitement to genocide and public incitement, in violation of international law.
Mohammad Mir Ali Mohammadi, spokesman for Iran's UN Mission, dismissed the letters, saying "it is bordering absurdity that Israel as the most egregious violator of human rights is complaining about human rights in Iran."
Iran insists its nuclear program is purely for peaceful purposes to produce nuclear energy.
The Israeli mission said the letter accuses Iran of violating major human rights treaties and operating extra-constitutional courts.
"In light of the aforementioned policies and practices," Carmon said, "it is patently obvious that Iran cannot honestly support open dialogue between civilizations and among member states."
In 2005, a U.N. committee passed a resolution expressing concern about human rights violations in Iran, deploring its use of amputation, torture and flogging.