April 21 (UPI) -- Negotiations aimed at facilitating the return of the United States to the Iran nuclear deal have made some progress in Austria, but officials say there's still a ways to go.
The United States and Iran began indirect negotiations in Vienna earlier this month to rejoin the accord, called the Joint Comprehensive Plan of Action. The latest round ended on Tuesday and the next round is set to begin next month.
Britain, France, Germany, Russia, China and the European Union are the remaining parties to the nuclear deal after the United States withdrew in 2018 under former President Donald Trump.
Iran has taken several steps over the past three years that violate the agreement, including enriching uranium at levels barred by the Obama-era pact.
"Participants took stock of progress made in the ongoing discussions in Vienna regarding specific measures needed in terms of sanctions lifting and nuclear implementation for the possible return of the U.S. to the JCPOA and its full and effective implementation," the Joint Commission of the Joint Comprehensive Plan of Action said in a statement.
"Progress made over the last two weeks," European Union negotiator Enrique Mora tweeted. "But much more hard work needed.
"I continue to think that diplomacy is only way forward for the JCPOA to address ongoing challenges."
Senior State Department officials later explained during a teleconference that "greater clarification" was achieved during the recent negotiations.
"I think the United States has a better idea of what it will need to do to come back into full compliance with the JCPOA, and Iran has a better idea of what it will need to do to come back into compliance with the JCPOA," the official said, adding that clarification though "doesn't necessarily mean consensus."
There are still disagreements, the official told reporters on the condition of anonymity, some of which are "pretty important."
"The distance that remains to be traveled is grater than the distance that we've traveled so far," the official said. "The outcome is still uncertain."
President Joe Biden has said he intends to use the JCPOA as a stepping stone to create a stronger and longer deal aimed at preventing Iran from achieving a nuclear weapon, which remains true, the official said.
Asked whether removing specific sanctions from Tehran to move talks forward was on the table, the officials said no.
"The discussions taking place in Vienna are about full compliance for full compliance," the official said, but adding that nothing had been ruled out.
"It's fair to say that there have been no breakthroughs, but we've always said that this process, even if it were going quite well, would not be easy or quick, and, of course, that remains true," he said.