April 6 (UPI) -- Indirect talks between the United States and Iran on Tuesday in Austria about a potential U.S. return to the 2015 nuclear deal were "constructive," an Iranian delegate said.
Abbas Araqchi, who lead the Iranian delegation, told state-run Press TV that the parties will hold further negotiations on the Joint Comprehensive Plan of Action on Friday.
"The talks in Vienna were constructive," he said.
Araqchi condemned, though, the United States' assertion that Tehran's demand for sanctions to be lifted first shows a lack of seriousness.
"That is quite logical and a very reasonable demand by the Islamic Republic of Iran," Araqchi said. "They have left the JCPOA, and they have imposed sanctions. So obviously if they want to come back, they will have to lift all those sanctions, all together, in one step."
The meetings in Vienna, hosted by the European Union, worked toward two separate agreements on how the United States and Iran can return to compliance with the deal's terms. Ahead of the talks, the U.S. State Department called them a "healthy step forward."
Though no face-to-face meeting is planned, the United States remains open to direct talks. Special envoy for Iran Rob Malley led the U.S. delegation, which met with European, Chinese and Russian counterparts.
Mikhail Ulyanov, a Russian diplomat who participated in Tuesday's talks, called them a success, but said a full agreement will take time.
"The restoration of #JCPOA will not happen immediately. It will take some time. How long? Nobody knows. The most important thing after today's meeting of the Joint Commission is that practical work towards achieving this goal has started," he tweeted.
Tehran and Washington are expected meet to finalize the details of any agreement once Iran and other participants produce a general proposal. The Iranian government had rejected direct U.S. talks offered in February.
Former U.S. President Donald Trump unilaterally withdrew from the accord in 2018, calling it a "bad deal," and reimposed economic sanctions that were lifted as part of the original agreement. New U.S. President Joe Biden, however, has said he wants to return to the Obama-era accord.
Under the deal, Iran agreed to international inspections and certain time-limited restrictions on its nuclear program. In exchange, sanctions were lifted by the United Nations, United States and other countries that signed on to the deal -- Britain, France, Germany, Russia and China.
The Biden administration has said it wants to lengthen and strengthen the original agreement.
"We don't underestimate the scale of the challenges ahead. These are early days. We don't anticipate an early or immediate breakthrough," State Department spokesman Ned Price said in a briefing Monday.
Iran's main goal in negotiations is the removal of all economic sanctions, Tehran said Monday. The sanctions should be removed in a single step, it said, and Iran will provide negotiating countries with a path that should be taken by the United States and a comprehensive list of sanctions to be lifted.
Biden has vowed to keep sanctions in place until Iran returns to compliance. But which of Tehran's frozen assets could be thawed, even with compliance, are not yet known. The State Department indicated Monday that the United States will lift only those related to Iran's nuclear program.
"We certainly will not entertain unilateral gestures or concessions to get Iran -- to induce Iran to a better place," Price added.
Iranian state-run Press TV reported the U.S. delegation will "leave Vienna empty-handed" if the Tuesday meeting results in anything other than the removal of all U.S. sanctions," citing an an informed source close to the Iranian negotiating team.