Official from country's atomic agency says move part of 60-day ultimatum laid down by President Rouhani for negotiating new terms

British general tells reporters that coalition forces have not detected any issues with Iran-backed forced in Iraq and Syria, drawing rare rebuke from US military and exposing rift

Spokesman for country's atomic agency insists actions ordered by President Rouhani in response to US sanctions do not violate 2015 agreement

Iranian Guards chiefs dismiss US 'psychological war,' say aircraft carrier deployed to region not a threat, but a target; 'If they make a move, we will hit them in the head'

'Things are heating up,' Yuval Steinitz warns as US aircraft carrier sails toward Persian Gulf; Iranian Guards chief dismisses US 'psychological war'

Foreign minister says Tehran's decision to back away from the nuclear deal and possibly restart high-level enrichment a 'bad reaction' to US moves

America maintains a vast network of bases, troops and assets throughout the region, to the chagrin of Tehran

Spokesperson says Tehran is eager to see landmark 2015 pact strengthened, as Europe says it won't cave to regime's 'ultimatums'

Iranians have threatened to undermine 2015 pact by restarting uranium enrichment if world powers fail to negotiate new terms. Will Washington's tough posturing pay off?

EU's foreign policy chief and foreign ministers of Britain, France, and Germany say they will assess Tehran's adherence to 2015 pact, remain determined to keep agreement alive