WASHINGTON—President Trump warned Hamas to free the remaining hostages in Gaza after the White House confirmed it had held face-to-face talks with the militant group on a deal to secure their release.

“Release all of the Hostages now, not later, and immediately return all of the dead bodies of the people you murdered, or it is OVER for you,” Trump posted Wednesday on social media. If the group continued to hold hostages, “you are DEAD!”