Iran walks back all prior concessions in nuclear talks, US official says

• Session was first with delegates from new Tehran government
• Iran says aerial explosion over Natanz was air defence test

Iran walked back all compromises made in previous talks on reviving the 2015 nuclear deal, pocketed compromises made by others and asked for more in its latest proposals, a senior US state department official told reporters on Saturday.

Iran continues to accelerate its nuclear program in pretty provocative ways and China and Russia were taken aback at how far Iran had walked back its proposals in talks in Vienna, the official told reporters, speaking on condition of anonymity.