"if everyone engages seriously, progress is possible," Bagheri Kani tweeted.
Bagheri Kani's Twitter message came on Wednesday evening after meeting with representatives of the remaining participants in the nuclear deal earlier on Wednesday in Vienna.
"Today I exchanged views with heads of delegations of UK, France, Germany, Russia, China, & EU," he added.
"Our experts also continue working on texts," the top negotiator further noted.
At the end of his tweet, Bagheri Kani wrote that "the last few days showed if everyone engages seriously, progress is possible".
The 7th day of Vienna nuclear negotiations passed as several meetings at various levels and frameworks were held with the aim of removal of the unlawful sanctions imposed by the US against Iran.
