TEHRAN, June 17. /TASS/. The negotiating parties at talks in Vienna are closer than ever to reviving the nuclear deal, the head of the Iranian delegation to the talks, Deputy Foreign Minister of Iran Abbas Araghchi said on Thursday.

"We are confident that the parties are closer than ever to concluding an agreement, but a number of key issues remain that must be discussed," Fars News Agency quoted him as saying. The parties "have achieved tangible progress on various issues at the talks," Abbas Araghchi stressed.

Negotiations between Iran and a five-member group comprising Russia, the United Kingdom, Germany, China and France, have been underway in Vienna since April.

Sustained progress was noted by all sides. Experts, divided into three working groups, work on the text of the upcoming agreement, in order to restore the implementation of the JCPOA in its initial state: with Washington withdrawing its sanctions from Iran, and Tehran returning to fulfilling its nuclear obligations. The representatives of JCPOA signatories hold separate consultations with the delegation of the US, that withdrew from the agreement in 2018, but intends to return now. There have been no direct talks between American and Iranian representatives in Vienna yet.