President Donald Trump says on social media that Israel and Iran have agreed to a “complete and total ceasefire” to be phased in over 24 hours.

The ceasefire announcement comes on the heels of a retaliatory strike from Iran on a U.S. airbase in Qatar on Monday.

CNBC rounds up the events of the last 24 hours, and lays out what could happen next. The past 24 hours have been pivotal in the Israel-Iran conflict, with the U.S. entering the war — a move that has left investors and world leaders on edge.