Iranian President Mahmoud Ahmadinejad said on Thursday that uranium enrichment was the essence of nuclear energy which Iran cannot give up, the official IRNA news agency reported.

"The essence of nuclear energy is the same as enrichment. Today, an International Atomic Energy Agency's (IAEA) official said there is no need for uranium enrichment in Iran," Ahmadinejad was quoted as saying in the southern province of Bushehr.

Ahmadinejad was referring to the IAEA chief Mohamed ElBaradei, who earlier in the day acknowledged Iran's right to access to peaceful nuclear technology but called on the Islamic Republic to suspend enrichment and other nuclear fuel work to build confidence.

Ahmadinejad further vowed that Iran will continue their efforts to restore their legitimate rights and will not yield.

The IAEA's 35-nation board of governors kicked off a two-day emergency meeting on Thursday in Vienna, Austria to discuss a resolution drafted by the European Union (EU) on the Iranian nuclear issue.

The draft resolution demands Iran to take various confidence building steps and requests ElBaradei to "report to" the UN Security Council these steps required of Iran.

Iran has said that there was no difference between reporting and referring of its nuclear case to the Security Council, warning that either will be followed by Iran's retaliating moves such as resuming uranium enrichment and curtailing snap inspections of the IAEA in its nuclear facilities.

The Iranian ambassador to the IAEA Ali Asghar Soltanieh restated in a written statement to the IAEA's board of governors that Iran will suspend all voluntary cooperation with the IAEA if the country's file went to the UN Security Council.

Meanwhile, Iran's chief nuclear negotiator Ali Larijani also sent a letter to ElBaradei to reinforce the threat.

The stepped-up tension over Iran's nuclear program came after Tehran defiantly resumed nuclear fuel research work on Jan. 10 and virtually rejected a Russian proposal to transfer its highly sensitive uranium enrichment program to Russia.

In response to Iran's move, the European trio of Britain, France and Germany, who long negotiated with Iran over the nuclear case, called for the IAEA's emergency meeting on Thursday.

The five permanent members of the UN Security Council - the United States, France, Britain, Russia and China - and Germany agreed on late Monday in London that the meeting should report the developments of the case to the Security Council.

Iran has repeatedly threatened that it will suspend voluntary cooperative measures, including suspension of uranium enrichment and the implementation of the additional protocol of the Nuclear Non-Proliferation Treaty according to a law ratified late last year.

Uranium enrichment is the key step for building nuclear fuel cycle, and highly enriched uranium can be used as material for nuclear weapons.

The United States has accused Iran of secretly developing nuclear weapons and the EU has asserted that Iran's full mastery of nuclear fuel cycle technology would possibly lead to military usage.

But Iran has insisted that its nuclear program is designed to meet rising domestic demand for electricity and that it is fully peaceful.

Source: Xinhua