Grossi: I may return to Tehran soon to continue the talks

"We are at a very important juncture," Grossi told Bloomberg TV in an interview on Tuesday, according to Ashura News, citing Tasnim news agency. "We know that a message has been sent by President Trump to the Supreme Leader of Iran by sending a letter."

He went on to claim, without considering the agreements made under the nuclear deal, that "it is clear that we need some kind of understanding that completely prevents Iran from obtaining a nuclear weapon."

Last week, Iran's permanent mission to the United Nations announced that it was reviewing its response to the letter and warned the United States that it would face severe blows if it carried out an aggressive act.

Earlier this month, Kazem Gharibabadi, the deputy foreign minister for legal and international affairs, visited the headquarters of the International Atomic Energy Agency and met with diplomats from China and Russia. Their joint statement said: "The three countries stressed that the relevant parties must commit to addressing the root cause of the current situation and abandon sanctions, pressure or threats of force."

“We are not where we want to be,” Grossi told Bloomberg. “Now these issues are coming together: on the one hand, these unresolved questions from the past; and on the other, the possibility of reaching a good agreement for the future.”

He added: “An agreement called the Joint Comprehensive Plan of Action (JCPOA) was signed in 2015 with a lot of ceremony, but that agreement no longer exists. Only its name remains.