Iranian and European delegations are expected to gather in Istanbul, Turkey, on Friday for fresh talks on Tehran's nuclear program, with European nations warning that a failure of negotiations may prompt punishing "snapback" sanctions on Iran.

Iran said it would continue nuclear talks with European powers after "serious, frank, and detailed" conversations on Friday, the first such face-to-face meeting since Israel and the U.S. bombed Iran last month.

Three European powers began meeting with an Iranian minister to try to reopen negotiations over the limits of its nuclear activities.