TEHRAN -- A senior advisor to Iran's Supreme Leader Ali Khamenei said on Thursday that if not making nuclear weapons by Tehran is the main issue in indirect talks with the United States, an immediate agreement is within reach.

Ali Shamkhani, who is secretary of Iran's Defense Council, made the remarks in a post on social media platform X while Tehran and Washington are holding a new round of nuclear negotiations in Geneva.

"If the main issue of the negotiations is not making nuclear weapons by Iran, this is in compliance with a religious decree issued by Iran's leader and the country's defense doctrine, and an immediate agreement is within reach," Shamkhani said.

He added that Iran's Foreign Minister Seyed Abbas Araghchi, who is heading the Iranian delegation in the talks, enjoys sufficient support and authority to reach such an agreement.

Shamkhani's remarks came as delegations of Iran and the United States started the third round of their indirect talks at Oman's Embassy in Geneva on Thursday morning amid heightened tensions between the two sides and a US military buildup in the West Asia region.

The first and second rounds of the negotiations were held earlier this month in the Omani capital Muscat and Geneva.