New International Atomic Energy Agency head Rafael Grossi ready to taker a harder attitude toward non-compliance with 2015 deal, diplomats say

Vienna meeting comes as European parties try to persuade Tehran to come back in line with the deal after taking steps away in protest at US pulling out and reimposing sanctions

Foreign Ministry in Tehran rejects 'unfounded' claim by UK, France, Germany that Tehran is violating the 2015 agreement

Parliamentary speaker responds to UK, France, Germany launch of dispute process charging Iran with failing to uphold terms of 2015 nuclear agreement, saying it's 'unfortunate'

Tehran says it will not observe curbs on uranium enrichment, stockpiles, research and development, but cooperation with UN watchdog will continue

Assistant head of country's Atomic Energy Organization says '50 new achievements' will be revealed next year

Rafael Grossi says he'll continue pressing Tehran about uranium particles found at Turquzabad facility described by Netanyahu last year as a 'secret atomic warehouse'

Rafael Grossi is unanimously confirmed as new IAEA leader, says inspections on Tehran's facilities should be done 'in firmness, but in fairness as well'

Rafael Grossi, praised for his energy, experience and innovation, takes over IAEA Monday, with landmark JCPOA teetering and Tehran hurtling toward restarting nuke program

With radioactive material found at location said to be the compound Israel brought to world attention, IAEA says it is 'essential' that Tehran help resolve matter