TEHRAN - Iran and the United States will enter the second round of indirect nuclear talks in Geneva on Tuesday, a senior Iranian diplomat told media.

Iran's Deputy Foreign Minister for Political Affairs Majid Takht Ravanchi made the confirmation in an interview in the Iranian capital Tehran with the BBC published on Sunday, elaborating on his country's preconditions for striking a deal with the United States.

Takht Ravanchi said the ball is in the US court to prove that it wants to make a deal, adding that if the United States demonstrates its sincerity, the renewed indirect talks between the two sides can lead to an agreement.

The first round of talks took place in the Omani capital Muscat on Feb 6.

Citing Iran's offer to dilute its 60 percent-enriched uranium as proof of the country's willingness to strike a deal, he said, "We are ready to discuss this and other issues related to our (nuclear) program if they are ready to talk about sanctions."

Iran's missile program is non-negotiable and the country does not accept depriving itself of its defensive capabilities, Takht Ravanchi said, adding, "Our understanding is that they have come to the conclusion that if you want to have a deal, you have to focus on the nuclear issue."

Takht Ravanchi ruled out the issue of zero uranium enrichment on Iran's soil, noting that as far as Tehran is concerned, "it is not on the table anymore."

Takht Ravanchi slammed the US military build-up in the West Asia region, warning that another war would be "traumatic, bad for everybody... everybody will suffer, particularly those who have initiated this aggression."

He added that Iran will respond accordingly to an existential threat, warning that waging a war against Iran will have regional consequences.

Describing the previous round of talks with the United States as having been "more or less in a positive direction," Takht-Ravanchi said Iran will head to the next round in Geneva with hope that a deal could be reached.

"We will do our best but the other side also has to prove that they are also sincere," he added.

The renewed diplomatic process between Iran and the United States comes amid heightened tensions between the two sides, and a US military buildup in the region.