Last month, US Secretary of State Antony Blinken said that Washington would ease some sanctions against Tehran if it returned to compliance with its commitments under the nuclear agreement.
"Their proposals are arrogant and insulting and do not even deserve to be looked at," Khamenei said on Iranian television, commenting on negotiations that are underway in the Austrian capital of Vienna.
Khamenei noted that while Washington conveys its desire for negotiations, it does not actually aspire to "accept the truth." Unlike the US, the EU acknowledges that "the right belongs to Iran," but the bloc depends largely on the US, he added.
According to the Supreme Leader, the extension of the negotiations would be harmful to Tehran.
In 2015, Iran signed the JCPOA with the P5+1 group of countries. The agreement required Iran to scale back its nuclear program and downgrade its uranium reserves in exchange for sanctions relief. In 2018, the US withdrew from the JCPOA and began imposing sanctions on Iran, being in violation of the nuclear agreement.
A year after Washington left the agreement, Tehran announced a phased reduction of its obligations under the JCPOA, abandoning restrictions in nuclear research, centrifuges, and the level of uranium enrichment.
In late 2020, Iran adopted a law to increase its uranium enrichment and stop International Atomic Energy Agency (IAEA) inspections of its nuclear sites in a bid to counter US economic sanctions. In early January, Iran's atomic energy organization announced that the country had succeeded in enriching uranium to 20% at the Fordow Fuel Enrichment Plant.
Since February 23, Iran has restricted IAEA inspections of the country's nuclear facilities. Besides, it has begun 60% uranium enrichment, a matter of concern for the commission parties, which is due to be one of the topics of the upcoming meeting in Vienna.