Iranian Foreign Minister Abbas Araghchi reiterated Wednesday that uranium enrichment remains a core part of Iran’s nuclear program and is "non-negotiable," responding to US Special Envoy Steve Witkoff’s recent demand that Tehran halt enrichment efforts.

"Iran's enrichment is a real, accepted matter. We are ready to build confidence in response to possible concerns, but the issue of enrichment is non-negotiable," Araghchi told reporters following a cabinet meeting.

On Saturday, his comments came ahead of a follow-up meeting with Witkoff in Oman, their second round of talks in a week and the highest-level engagement between the two countries since Trump exited the 2015 nuclear deal in 2018 and reimposed sweeping sanctions on Tehran.

After returning to office in January, Trump sent a letter to Iran’s Leader, Sayyed Ali Khamenei, calling for dialogue but warning that failure to reach an agreement could result in military action.

While both sides described their previous talks as "constructive," tensions escalated after Witkoff said Tuesday that Iran must “stop and eliminate” uranium enrichment, a shift from his earlier position, which only demanded Iran return to the 3.67% enrichment cap outlined in the original nuclear accord.

Araghchi criticized the Trump administration’s "contradictory and conflicting positions," and said Iran would assess Washington’s real stance in the upcoming negotiations. He also emphasized that any progress would depend on consistent and constructive positions from the US.

“If we continue to (hear) contradictory and conflicting positions, we are going to have problems,” he warned.

'Lack of trust remains'

Indirect negotiations between Iran and the United States in Oman have been carried out effectively in their early stages, though the Islamic Republic remains skeptical toward the other side, Iranian Leader Sayyed Ali Khamenei said on Tuesday.

“We are neither excessively optimistic nor overtly pessimistic about these talks,” he stressed, “Of course, we are very distrustful about the other side," speaking to the leaders of the Islamic Republic’s executive, judicial, and legislative branches.

The Leader of Iran pointed out that the talks were among the various matters handled by the Foreign Ministry, emphasizing that it was an action and a measure that had been both decided upon and implemented.

He further pointed out that progress in the Islamic Republic's diverse affairs should not be tied to the negotiations, insisting that the nation must advance its various matters autonomously while depending on its capabilities.

“Let us not tie the country’s issues to the talks,” he said, emphasizing that despite Iran's immense skepticism regarding talks, he noted that Tehran is optimistic about its capabilities.

These comments followed discussions between Iran and the US in Muscat last Saturday, where Oman's foreign minister acted as the intermediary.