An Iranian official said Sunday that Iran has so far produced over 50 kg 20-percent enriched uranium and still needs to speed up the production.

During an exclusive interview with Xinhua, Iran's permanent representative to the International Atomic Energy Agency (IAEA) Ali-Asghar Soltanieh, said that the recent plan to speed up the production of the 20 percent enriched uranium is aimed at providing fuel for Tehran research reactor.

Iran has announced Wednesday that the country will triple its 20 percent uranium enrichment output.

Asked about the reasons behind the increase, Soltanieh told Xinhua that "we need 120 kg enrichment up to 20 percent. Of course, we have been able to produce successfully over 50 kg."

"But we still need (more), we have to speed up," he said, adding "because Tehran research reactor is in desperate need for fuel, because Tehran reactor should produce radioisotopes for hospitals."

Blaming the Vienna group for the failure of providing the 20 percent enriched uranium for Tehran research reactor, he said that the group, comprising France, Russia and the United States, has lost the chance.

In a tripartite meeting in Tehran in 2010, Iran signed an agreement with Turkey and Brazil, dubbed Tehran Declaration, to endorse a fuel swap deal, in which Iran agreed to ship most of its low enriched uranium to Turkey in exchange for the 20 percent uranium fuel needed for its Tehran research reactor.

Talking to Xinhua on the sidelines of an international nuclear disarmament conference in Tehran on Sunday, Soltanieh said that Iranian parliament has passed the bill for building more nuclear power plants in the country in future to produce some 20,000- megawatt electricity.

He said that Iran will welcome any countries which are ready to participate in the projects which will be carried out under the complete surveillance of IAEA.

Last summer, the Atomic Energy Organization of Iran (AEOI) announced that the country had plans to build 20 more nuclear power plants to meet the country's energy demands.

Iran's Foreign Minister Ali-Akbar Salehi said Tuesday that his country is getting ready to connect its first nuclear power plant Bushehr plant to the national grid in one month.

Concerning Iran and the five permanent members of the UN Security Council plus Germany (G5+1) nuclear talks, Soltanieh repeated Iran's stance by saying that "Iran has been always ready and prepared for negotiations without any preconditions."

He blamed the G5+1 for creating deadlock in the nuclear talks.

In January, the six world powers wrapped up crucial nuclear talks with Iran in Istanbul but failed to reach any agreement on the Iranian nuclear program.