During the most recent meetings, Iran added demands unrelated to discussions about its nuclear program and has made troubling progress on uranium enrichment, according to the US envoy for talks on reviving a nuclear agreement.

According to US Special Envoy for Iran Robert Malley, a proposal for a date by which Iran may return to compliance with the nuclear agreement and Washington could lift sanctions on Tehran is on the table.

Some of the requests were rejected by the US and Europe as being unworkable in discussions.

The nuclear agreement curtailed Tehran’s uranium enrichment program, which might lead to nuclear weapons, despite Iran’s claim that it solely seeks civilian nuclear energy.