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.

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.

Trump on Monday said that the 12-day conflict between Israel and Iran is coming to an end with a ‘complete ceasefire’ that will be phased in over 24 hours. He called the announcement proof that his decision to order airstrikes on Iran’s nuclear sites was justified.