U.S. President Donald Trump says Iran has proposed negotiations after his threat to strike the Islamic Republic as a crackdown on demonstrators has led to hundreds of deaths.

At least 572 people have been killed as security forces try to quash the unrest, activists say, with the true scale of the crackdown yet to become clear amid an internet blackout.

“Protests across Iran are escalating and may turn violent, resulting in arrests and injuries. Increased security measures, road closures, public transportation disruptions, and internet blockages are ...