The visit by the envoy, Steven Witkoff, was set to take place as Israeli and Hamas officials prepared for a new round of negotiations aimed at cementing the current cease-fire in Gaza and allowing more exchanges of hostages and Palestinian prisoners.

Already, the fragile deal has come under considerable stress, and it could collapse in the weeks to come. Yet for the time being, the fighting has stopped in both Gaza and Lebanon, and hostages have begun to come home.