India and Pakistan agreed to an immediate ceasefire on Saturday, unexpectedly halting the worst fighting in decades between the nuclear-armed neighbors, just when their tit-for-tat strikes appeared to be spiraling out of control.

The truce came after several days of the countries’ most expansive fighting in decades. One Indian official said the country would “deal strongly” with any violations.

The first word of the truce came from President Trump, who announced that the two countries had reached a "full and immediate ceasefire," after talks mediated by the U.S.