President-elect Donald Trump on Monday demanded that the Hamas terrorist group immediately release the Israeli hostages it holds in Gaza, warning on his Truth Social platform that there would be “HELL TO PAY” if the hostages haven’t been freed before he takes office on Jan. 20.

The Biden administration has been working unsuccessfully for months to reach a ceasefire agreement and gain the hostages’ release. Trump’s threat that “Those responsible will be hit harder than anybody has been hit in the long and storied History of the United States of America” arrived amid a fresh push for a ceasefire. Hamas representatives met with Egyptian security officials in recent days to discuss the matter, amid signs that the group has become more flexible in its demands.

The urgency Trump brings to this issue is welcome, even if it isn’t clear what he could do, as president, to hit Hamas harder in Gaza than Israel is already doing. His leverage against Iran as well as Hamas leadership abroad, however, may be greater. Hamas still holds 101 hostages, among them seven U.S. citizens. The hostages have been captive under brutal conditions for more than 420 days, and reports indicate that about half of them are still alive.

The terrorist group has suffered devastating losses during 14 months of Israeli action after its Oct. 7, 2023, attack on Israel. Although not destroyed, Hamas can now only wage a low-level insurgency. That fact, plus Israel’s killing of Hamas leader Yahya Sinwar in October, might make the group inclined to strike a deal before Trump takes office.

What would a deal for a ceasefire and hostage release look like? The United States, Egypt and Qatar have mediated the outlines of a potential deal.

According to news reports and Israeli sources, the first phase would involve a six-week truce, during which Israeli military forces would maintain positions in Gaza while hostage and prisoner exchanges occur.

Thirty-three living and dead Israeli hostages, including all female captives, would be swapped for Palestinian prisoners, setting the stage for securing additional hostages and negotiating a permanent ceasefire.

If the second phase faltered in not reaching a deal to return the remaining hostages, Israel would retain the right to resume operations against Hamas without being considered in breach of the agreement. This approach offers more flexibility than the already wobbling ceasefire with Hezbollah in Lebanon.

The potential deal hinges on two issues: Israel’s control of the Philadelphi Corridor on Gaza’s southern border with Egypt, and the type of Palestinian prisoners Israel is willing to release.

The Philadelphi Corridor has been a smuggling route for Hamas. If Egypt cooperates — some added Trump pressure here might be helpful — this risk can be mitigated through advanced technology and specialized forces. In the Oct. 7 attack, an underground barrier built by Israel blocked the construction of tunnels that might have led to an even worse slaughter. The barrier demonstrated the potential for using similar systems on the Gaza-Egypt border.

In earlier ceasefire negotiations, Hamas demanded Israel’s complete relinquishing of the Philadelphi Corridor. Recently, the group signaled that it might relax that requirement during the first phase of the deal. Regardless, Israel’s military superiority ensures that it could retake the area swiftly if talks collapse. Again, an expression of public support from Trump regarding Israel’s right to reenter the area might prove useful.

The release of Palestinian prisoners in exchange for hostages is one of the most contentious matters for negotiators. Hamas seeks the release of fighters who have Israeli blood on their hands. The 2011 exchange of 1,027 prisoners, including Sinwar, for Israeli soldier Gilad Shalit set a grim precedent, as many returned to violence.

Hamas has also, in negotiations since Oct. 7, 2023, demanded that many of the released prisoners be sent back home to the West Bank, with some of the more dangerous relocated to Gaza or abroad, according to Israeli sources and reports on the draft agreement. The concern: They could conduct further attacks. Though hardly guaranteed success, over time, Israeli forces can track released prisoners and neutralize emerging threats. The United States must commit to supporting these efforts.

Israel’s strength offers a rare chance to prioritize the return of hostages. A Channel 12 poll shows 71 percent of Israelis support ending the Gaza war in exchange for the hostages’ freedom, with only 15 percent opposed. Notably, 56 percent of Prime Minister Benjamin Netanyahu’s right-wing bloc voters favor a hostage deal and ceasefire.

President Joe Biden deserves credit for his efforts to secure the hostages’ release. But only Israel’s success in eliminating thousands of Hamas fighters and destroying the group’s leadership is what will force Hamas into serious negotiations.

The threat issued by Trump on Monday, with luck, will have an accelerating effect.

If a deal can indeed be made before he takes office, he can justifiably claim a share of the credit. This moment demands decisive leadership and bipartisan support — perhaps the last chance for the hostages and their families.

Mark Dubowitz is chief executive of the Foundation for the Defense of Democracies.