Marco Rubio, the secretary of state, later described Mr. Boehler’s meetings as a “one-off” that had yet to produce results.
But Hamas’s latest offer was similar to what Mr. Boehler proposed last week in Doha, which included a plan to jump-start negotiations for the second phase and bring home the remaining hostages, said a U.S. official, who spoke on condition of anonymity because the person was not authorized to speak publicly. That proposal followed days of talks that Mr. Boehler conducted in close coordination with Mr. Witkoff, the official said.
Up to 24 living hostages and the bodies of more than 30 others are still in Gaza, according to the Israeli government.
Hamas and other militant groups seized about 250 hostages during the Oct. 7, 2023, attack on southern Israel that ignited the war in Gaza. More than 100 have returned alive to Israel after deals with Hamas in exchange for Palestinian prisoners. Israeli soldiers retrieved the bodies of dozens of others during the ground invasion of Gaza.
In mid-January, Israel and Hamas signed off on the multiphase cease-fire, during which 30 hostages and the remains of eight others were exchanged for more than 1,000 Palestinian prisoners over the first six weeks of the truce. The release of others — like Mr. Alexander — was deferred until both sides concluded talks on the nebulous “second phase.”
Mr. Alexander grew up in Tenafly, N.J., with Israeli-born parents. After high school, he moved to Israel to enlist in the military; he was abducted from the post where he was stationed during the Hamas-led attack. Hamas published a hostage video in which he appeared last year.
The prospect that captives holding another nationality — like Mr. Alexander — might be prioritized has already prompted furious denunciation from the relatives of Israeli hostages held in Gaza. Many have called for a single agreement that frees all the remaining captives at once.
“If Israel insists on stopping in the middle and leaves its citizens behind — let every Israeli mother know that she must get her son a foreign passport, or else he’ll be abandoned,” the Hostage Families Forum, an advocacy group, said in a statement.