"Efforts by the big powers will only incite anger and hatred," Mahmoud Ahmadinejad told a large crowd on the outskirts of Tehran. "The Iranian nation will respond to restrictive activities with an appropriate and firm response," he said without elaborating.
The hardline Iranian president gave his speech as key United Nations Security Council members were deliberating a draft European resolution that would impose sanctions on Iran over its disputed nuclear program.
Meanwhile, Mohamed ElBaradei, who heads the International Atomic Energy Agency, said at the U.N. that his organization has not been able to verify that Iran's nuclear program is peaceful.
Security Council permanent members Russia and China have shied away from imposing punitive measures on their trade partner Iran, saying they prefer a diplomatic solution to the impasse. But the United States says the proposed sanctions are not tough enough.
The Russian president told his Iranian counterpart on Monday that Russia strongly favors further negotiations on Tehran's nuclear program, the Kremlin said.
The brief Russian statement after a telephone conversation between Vladimir Putin and Ahmadinejad was the latest indication that Russia opposes sanctions against Iran and believes the international community should try to defuse tension through talks.
With Iran waving threats of d of the U.N. nuclear watchdog, said that the IAEA was "unable at this stage to confirm the peaceful nature of Iran's nuclear program which, obviously, is a matter of serious concern."
ElBaradei referred to his earlier report to the Security Council verifying that Iran had ignored the Aug. 31 deadline to halt uranium enrichment.
The IAEA had not been able to "make progress resolving the outstanding issues — issues that require certain transparency measures on the part of Iran," said ElBaradei.
Also Monday, Iranian Foreign Minister Manouchehr Mottaki indicated that Tehran expects Russia and China to support it Iran in the council deliberations.
"We are hopeful these countries would support Iran's reasonable stances as much as possible," Mottaki told reporters on the sidelines of an economic conference. "However, we only count on support by our nation."
Mottaki also urged the U.N Security Council to avoid "illegal and incorrect decisions" — a reference to Iran's claim that as a member of the Nuclear Nonproliferation Treaty it has the right to pursue a peaceful atomic energy program.
"I repeat again here that threatening and imposing sanctions could not keep the nation from achieving its inherent rights," he said.
The European members of the council — Britain, France and Germany — met last week to discuss the draft resolution.
On Monday, all six permanent Security Council members were expected to continue deliberations.