IAEA chief Grossi says Iran using a special setup that allows it to swiftly switch between enrichment levels; Tehran reportedly has 43 kilograms of uranium enriched to 60% purity

New York Times says US and Israeli officials have been monitoring new construction at Natanz for a year; Defense Minister Gantz first alluded to site in speech last month

Meeting comes amid stalled Iran nuclear talks, and days after Israeli prime minister published documents he said prove Iran spied on IAEA

PM rebuffs Iranian foreign minister's claim that alleged spying operation is just 'Zionist lies'; proof 'is here in my hands,' he says

Iranian atomic energy organization says Tehran 'obliged to intensify security measures' by shifting some machinery to Natanz, which was also a target of reported Israeli attacks

Assertion by Tehran's nuclear chief contradicts reported draft terms of accord being negotiated in Vienna, which are said to restrict enrichment to 5%

Mohammad Eslami insists Tehran will not further approach weapons-grade uranium should efforts to restore the 2015 accord collapse

Refusing to slow down advances in its atomic program, Tehran further raises the stakes in talks crucial to cooling years of tensions boiling in the wider Mideast

IAEA says Tehran began process of enriching to up to 20% at site dug into mountain, as negotiators fear it's creating facts on the ground

Tehran capable of producing 90% enriched uranium within weeks, defense figures have reportedly warned American officials, as talks restart in Vienna