Trump says Tehran downed American military helicopter and pledges retaliation.

The president says the Middle Eastern country downed United States war chopper and pledges retribution.

Secretary-General 'Profoundly Disturbed' by Renewed Escalation in Mideast White House urges artificial intelligence laboratories to cease reports amid national security worries. Flying robots impacted old museum in Russia-annexed peninsula as officials decrease nighttime railways for protection Battles between Israel and Iran are 'very important', commentator says. The commander-in-chief says negotiations with the Iranian government remain ongoing, with agreement possible in two or 3 days.