TEHRAN, April 14 (Xinhua) -- Iran's Supreme Leader Ayatollah Ali Khamenei on Wednesday reiterated Tehran's position that U.S. sanctions must be lifted before Iran returns to its compliance with the 2015 deal, known as the Joint Comprehensive Plan of Action (JCPOA).

"The officials' assessment is to go and negotiate in order to implement that policy, and we have no objection in this regard," Khamenei said in a public event, as quoted by his official website.

Talking through videoconference in a religious ceremony broadcasted to celebrate the first day of the holy month of Ramadan, Iran's supreme leader stated that the U.S. officials' expressions of readiness to negotiate do not mean that Washington is ready to "listen and accept what is fair," but are rather a sign of their determination to "impose their unjust position."

The United States "has not kept its promises on dozens of occasions," he said.

The JCPOA resumed talks in Austria's capital Vienna on April 6. The U.S. government has sent representatives to take part in the process, but Tehran has until now refused to meet them, since Washington abandoned the JCPOA in May 2018 and unilaterally reimposed sanctions on Iran.

This week, voices were clearly heard in Iran asking the government to halt the Vienna talks after the Iranian uranium enrichment plant in Natanz suffered an attack on April 11, which Iran has accused Israel of the "sabotage."