Iran Press/Asia: The jet was flying some 135 km (84 miles) east of northern Japan at about 7:27 p.m. (1027 GMT) when it dropped off radar, the military said.
Details remain extremely limited at this time, but there are reports from Japanese media outlets stating that one of the Japan Air Self Defense Force's F-35As has gone missing during an evening training mission off Northern Japan. A search effort is now underway, Reuters reported.
That's what we have as of now and keep in mind that these are media reports, not official statements. So, these details could change dramatically in the coming hours.