European and Iranian diplomats have arrived in Istanbul in a renewed effort to resolve the standoff over Tehran's nuclear program. The talks mark the first formal engagement since June's 12-day war between Iran and Israel, a conflict that included U.S. airstrikes on Iranian nuclear facilities and heightened tensions across the region.

Iranian and European officials will hold nuclear talks in Istanbul on Friday as tensions simmer over Tehran’s nuclear program after it was targeted by a US military strike last month.

The so-called E3 - Britain, France and Germany - have warned they will invoke the United Nations snapback mechanism to reimpose international sanctions on the Islamic Republic.