The UN Secretary-General called on Iran Wednesday to hold a “serious dialogue” with its nuclear watchdog, the IAEA, during the ongoing nuclear deal negotiations.

Ahead of the start of the UN General Assembly, Antonio Guterres said the International Atomic Energy Agency’s “independence exists, must be preserved and is essential. The IAEA cannot be an instrument of parties against other parties.” 

Tehran’s demands that the IAEA shut its probe into suspected Iranian nuclear activity have become a key sticking point as the talks to revive the 2015 deal drag on.

Also on Wednesday, EU foreign policy chief Josep Borrell described the talks to bring Iran and the US back into the deal as an “stalemate,” saying that “I am afraid that with the political situation in the US, and so many directions without being conclusive, now we are going to stay in a kind of stalemate.”

He added that over the past couple of months, “the proposals were converging but unhappily, after the summer, the last proposals are not converging -- they are diverging,” highlighting that “The last proposals from the Iranians were not helping because we were almost there, then new proposals came and the political environment is not the most propitious. I am sorry to say, but I don't expect any breakthrough in the next days.” “From my side, I don't have anything more to propose.” 

Later in the day, two-thirds of the IAEA's 35-nation Board of Governors endorsed a non-binding statement by the United States, Britain, France and Germany pressing Iran to explain about uranium traces found at three undeclared sites.