White smoke may be rising from Vienna soon where world powers and Iran appear to be getting closer to agreeing on how to revive the 2015 nuclear deal that United States President Donald Trump abandoned from in 2018, with all sides expressing varying signs of optimism.

Josep Borrell, the European Union foreign policy chief, said Monday [April 19] that he saw "real good will" with both Iran and the US willing to take steps that would see the US return to the 2015 agreement, the Joint Comprehensive Plan of Action (JCPOA). "That’s good news," Borrell told reporters.

Borrell said talks were "more focused" on the joint tasks of agreeing which US sanctions were incompatible with the JCPOA and which aspects of its nuclear program Iran needed to reverse to again meet JCPOA limits. Borrell explained that he had spoken separately last week with US Secretary of State Antony Blinken and Iranian Foreign Minister Mohammad Javad Zarif and found both "really interested in reaching an agreement.”

Before Borrell's optimistic remarks, Mikhael Ulyanov, the Russian ambassador to the International Atomic Energy Agency tweeted that talks had "entered the drafting stage,” which involved “agreeing on specific steps towards the goal."

Wang Qun, the Chinese IAEA ambassador, on Saturday had said all parties had agreed to "more extensive, substantive work on sanctions-lifting as well as other relevant issues." Wang expressed the hope that with the following few days the JCPOA Joint Commission would “immediately start negotiating the specific formula of sanction-lifting.”

Iranian officials have since a Wednesday speech by Supreme Leader Ali Khamenei adopted a positive tone. Foreign ministry spokesman Saeed Khatibzadeh said Monday the talks in Vienna are "on the right path."

A US delegation is stationed in Vienna for the talks but is not part of formal JCPOA structures including the Joint Commission. The US National Security Advisor Jake Sullivan Sunday told Fox News the talks were "constructive in the sense that there is real effort underway there."

The Israeli government, which has opposed the JCPOA and has been widely held responsible for the April 11 attack on Iran’s Natanz nuclear site, has tried to convince the Biden administration to continue Trump's ‘maximum pressure.’ But Israeli officials who attended a Mossad briefing of the cabinet on Sunday told Axios said they would not be surprised if agreement on reviving the JCPOA was reached within weeks between Iran and world powers, including the US.