U.S. and Iranian officials are meeting in Vienna, Austria, to begin indirect talks on reviving the 2015 nuclear deal.
Officials from Russia, China, France, Germany and Britain — the other parties to the pact — will also attend.
Former President Trump pulled out of the deal in 2018 and then reimposed sanctions on Iran as part of his so-called "maximum pressure" campaign.
On Monday, State Department spokesman Ned Price called the meeting a "healthy step forward" but said the U.S. expects the discussions to be difficult.
