Iranian President Mahmoud Ahmadinejad speaks at a news conference in Tehran Jan. 14. (Reuters)

Iran said on Saturday that it will never give in under pressure to halt its recently resumed nuclear research work even if its nuclear file was referred to the UN Security Council, but called for more talks to solve the current standoff.

"Our position is very clear: we are carrying out nuclear activities according to the Non-Proliferation Treaty (NPT) and the International Atomic Energy Agency's (IAEA) regulations. Asking us to stop nuclear research is beyond such conventions," Iranian President Mahmoud Ahmadinejad told reporters at a press conference earlier in the day.

"Nuclear research is our natural right and we had suspended it voluntarily. Now, we will resume them," Ahmadinejad added.

Iran on Tuesday removed seals on research facilities at three nuclear sites and resumed nuclear fuel research work suspended for more than two years under the supervision of the IAEA, incurring condemnation of the European Union, the United States and some other countries.

Meanwhile, Iran has also rejected a proposal of Russia to establish joint uranium enrichment venture on Russian soil.

In response, the EU trio of Britain, France and Germany on Thursday said that the nuclear talks with Iran had been at a dead-end, calling for an emergency session of the IAEA to vote on referring Iran's nuclear case to the UN Security Council, which could lead to sanctions on the Islamic Republic.

The United States has repeatedly expressed support to the EU call of referral but ruled out military actions on Iran.

Meanwhile, Ahmadinejad slammed the EU's call as "forcing the IAEA to adopt political resolutions on Iran", vowing that Iran "would not be bullied" even at the UN Security Council.

"The IAEA should be an undoubtedly authoritative international body dealing with nuclear issues, but what they (the EU and the U.S.) are doing will damage the credit of the IAEA," he stressed.

However, the hardline president did not recall a threat of stopping cooperation with the international community made by the country's Foreign Minister Manuchehr Mottaki on Friday.

"If the case dossier is referred to the Security Council, the European countries will lose the current means (to solve the Iranian nuclear issue). The government must cease all voluntary measures of cooperation according to the law," Mottaki told the official IRNA news agency.

The Iranian Majlis (Parliament) last November approved a law which requires the government to cease all voluntary confidence-building measures if the country's nuclear case were taken to the Security Council.

Tehran defines the suspension of uranium enrichment and the implementation of the additional protocol of the NPT, which allows UN inspectors to carry out snap inspections, as voluntary measures to build confidence.

Later on Saturday, the Iranian Foreign Ministry issued a statement, saying that the EU "has no right to expect Iran not to go ahead with research work on utilizing nuclear energy for civilian purposes."

"It is surprising that the European states have embarked on an illogical drive against (Iran's) resumption of research studies. It is surprising that they interpret their illogical approach toward the Iranian nuclear program in a way that they are right to fabricate new charges everyday," according to the statement, cited by IRNA.

However, the statement also called for the EU to continue negotiations to solve the disputed nuclear issue.

"Iran believes that the standoff with the EU about the nuclear program should be settled by negotiations and advises the European partners to be rational in dealing with Iran and Iran's rights," it added.

Tehran and the EU were previously scheduled to hold another round of talks on Jan. 18, but the EU had said that Iran's restart of nuclear research would endanger the negotiations.

Hossein Entezami, spokesman of Iran's Supreme National Security Council, was quoted by IRNA as saying on early Saturday that the bilateral nuclear talks would not touch on the Islamic Republic's nuclear research.

"Nuclear research is a totally independent subject and Iran has already informed the IAEA and Europe regarding this matter. Iran and the EU will just discuss the issue of uranium enrichment," Entezami said.

"Russia's proposal, the continuation of talks with Europe and cooperation with the IAEA were three entirely separate issues," the spokesman added.