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.

WASHINGTON—Nuclear-armed rivals India and Pakistan have agreed to a ceasefire following U.S.-led talks to end an intensifying military confrontation, President Donald Trump announced in a post on his Truth Social media platform Saturday morning.