Donald Trump speculates 'terrorist attack' downed EgyptAir flight
"When will we get tough, smart and vigilant? Great hate and sickness!" Trump tweeted.
Trump's speculation came before Egypt's aviation minister reportedly said the plane was "more likely" brought down by terrorism than a technical failure.
French President Francois Hollande confirmed the crash of the plane, which authorities said was carrying 66 people.
Egypt's aviation minister had said earlier Thursday that investigators were not ruling out any scenario, including terrorism. But he also cautioned against "hypothesizing" about the plane's demise before investigators locate the plane's wreckage.
The presumptive Republican presidential nominee has a history of speculating about plane disappearances.
Following the disappearance of Malaysia Airlines Flight 370 disappearance in 2014, Trump occasionally tweeted updates about the plane. In March of 2014, he floated a theory that exploding lithium ion batteries destroyed the plane. He also complained that the US was footing a disproportionate share of the bill to find the plane.