He indicated in a series of tweets that the deaths would not be “proportionate to shooting down an unmanned drone.” An Iranian surface-to-air missile brought down an American surveillance drone on Thursday. Here are the latest updates.

Closer look: Mr. Trump has said the aircraft was over international waters when it was destroyed, while Iran said it had strayed into its airspace. Here’s a map of the disputed locations.

News analysis: Mr. Trump has alternated between threatening America’s enemies and promising to get the U.S. out of foreign conflicts. He may now have to choose, our chief White House correspondent writes.

The Daily: Today’s episode discusses how the U.S. and Iran got to this point.

Related: The Senate voted to block a multibillion-dollar arms sale to Saudi Arabia and the United Arab Emirates. The vote came after the Trump administration tried to circumvent Congress to allow the exports by declaring an emergency over Iran.