Iran will never suspend its uranium enrichment program and there is no justification to close the Fordo underground site, an Iranian envoy said on Friday, making clear Tehran's red lines in talks with world powers later this month.

Last month a senior U.S. official said the United States and its allies would demand that Iran halt higher-grade uranium enrichment and immediately close the Fordo facility at talks over Tehran's nuclear standoff with the West.

But Iran's ambassador to the International Atomic Energy Agency (IAEA), Ali Asghar Soltanieh, told Reuters he saw "no justification" for closing Fordo, which he said was under IAEA surveillance.

"When you have a safe place, secure place under IAEA control, then why do you tell me that I should close it," he said.

Soltanieh spoke ahead of an upcoming round of nuclear talks set to be held in the Iraqi capital of Baghdad later this month, following initial talks held in Istanbul.

Referring to Baghdad talks on Thursday, Iran's Foreign Minister Ali Akbar Salehi told Iran's state TV that participants should set a new framework to the negotiations.

“Experts of the two sides should draw a plan to determine next steps in a transparent way and prepare the grounds for building confidence,” Salehi told Press TV.