Israeli Prime Minister Benjamin Netanyahu accused the Iranian president of being “a wolf in sheep’s clothing” at a U.N. General Assembly speech.

(CNN) — In a speech Tuesday to the U.N. General Assembly, Israeli Prime Minister Benjamin Netanyahu accused the Iranian president, Hassan Rouhani, of being “a wolf in sheep’s clothing; a wolf who thinks he can pull the wool over the eyes of the international community.”

Western leaders have expressed guarded optimism about Iran’s more moderate tone under Rouhani, whose recent comments have raised hopes that a deal could be struck over the Middle Eastern nation’s nuclear program.
But Netanyahu urged world leaders not to be duped by Rouhani’s demeanor, calling him a “loyal servant” to the Islamic regime, which he said “executes political dissidents by the hundreds” and jails them by the thousands.

“It’s not hard to find evidence that Iran has a nuclear weapons program,” Netanyahu said. “It’s hard to find evidence that Iran doesn’t have a nuclear weapons program.”

Tehran has insisted that its nuclear program is intended solely for peaceful purposes, but Netanyahu said that, even since Rouhani took office in August, “this vast and feverish effort has continued unabated.”

Rouhani “thinks he can have his yellowcake and eat it, too,” Netanyahu said, in a reference to the raw uranium ore that can be processed into nuclear weapons.

International sanctions have left Iran “on the ropes,” the Israeli prime minister told the world body, whose Iranian representative was not present. He called for the sanctions to remain in place to force Iran to halt its nuclear aspirations. “We all want to give diplomacy with Iran a chance to succeed,” he said. “But when it comes to Iran, the greater the pressure, the greater the chance.”