Iran has criticized as "worthless" recent remarks by a top US official that Iran does not need some of its nuclear establishments.

"Some remarks, even if they are meant for domestic use, will ruin the atmosphere for reaching a solution" on Iran's nuclear issue, Iranian Foreign Minister Mohammad-Javad Zarif was quoted as saying by Tehran Times daily in its Thursday editions.

"They themselves know that the issues which they are raising in response to pressure from inside United States are against the nuclear agreement and negotiations," Zarif said.

He was referring to statements made Tuesday by US Undersecretary of State Wendy Sherman that Iran does not need to have an underground, fortified enrichment facility like Fordow or its heavy-water reactor at Arak.

Those comments are not relevant to the recent nuclear deal, Zarif said.

Iran has maintained that the Islamic republic's nuclear program is for peaceful purposes only and that its right to nuclear technology is non-negotiable. It insists that its nuclear research doesn't violate the interim agreement Iran reached with world powers last year.

"In fact, the best part of Joint Plan of Action (the interim nuclear deal) is the research part of it," Head of Atomic Energy Organization of Iran Ali-Akbar Salehi said. "It's so clear that research and development have no constraints," Salehi told Press TV, referring to Sherman's comments that Iran should stop working on development of advanced centrifuges.



The Iranian atomic chief refuted demands made by some Western countries that Iran dismantle part of its installed centrifuges.

"Out of roughly 18,000 centrifuges in Iran's possession, 9,000 of them are working and are functioning, and (by the recent agreement) we have voluntarily accepted not to inject gas into the other 9,000," he said.

"The only thing we have stopped and suspended, which is voluntarily, is the production of 20-percent enriched uranium and that's it," Salehi told Press TV, emphasizing that Iran will continue its nuclear activities and increase the production of 5 percent enriched uranium.

On Jan. 20, Iran and the P5+1 group, which includes the five permanent members of the United Nations Security Council -- United States, Russia, China, France, Britain -- and Germany, started implementation of the interim nuclear deal they clinched in Geneva on Nov. 24, 2013.

Under the agreement, Iran suspended 20-percent uranium enrichment and started the process of diluting and oxidizing its 196 kg stockpile of 20-percent enriched uranium in exchange for partial relief of the sanctions imposed on its energy and financial sectors.