A ceasefire deal was reached Wednesday to end 15 months of fighting in the Gaza Strip, according to President Joe Biden, Qatar’s prime minister and Hamas officials. The hard-won agreement will also free dozens of hostages held in Gaza, as well as Palestinians in Israeli jails, bringing the first real break in violence since a weeklong truce expired Dec. 1, 2023. The deal will take effect Sunday, according to Qatar’s prime minister and foreign minister, Sheikh Mohammed bin Abdulrahman Al Thani, whose country hosted weeks of intense negotiations. Under the phased agreement, Israeli forces would withdraw to the Gaza border, allowing displaced Palestinians to return to their homes and for the transfer of hostages and prisoners. Large amounts of humanitarian aid would be shipped to the enclave and hospitals and health care centers would be rebuilt, he said. Hamas, meanwhile, will release 33 hostages in exchange for 100 Palestinian prisoners with life sentences, according to a portion of the deal shared by Hamas. The first phase would see the release of civilians, children, elderly and wounded hostages. American hostages Sagui Dekel-Chen and Keith Siegel are alive and expected to be released in the first phase of the Israel-Hamas ceasefire deal, a senior administration official told NBC News. Siegel is in his 60s and his wife, Aviva, was among those released in the 2023 temporary ceasefire agreement. Dekel-Chen turned 36 while in captivity, and his father, Jonathan, told NBC News that his family has not heard about his condition in roughly a year. Israel will also release 1,000 Palestinian prisoners who were not involved in the Oct. 7 attacks, the text says, and an unspecified number of Palestinian prisoners will also be released abroad or in Gaza. In a statement, Biden hailed “many months of intensive diplomacy” by the U.S., Egypt and Qatar. “My diplomacy never ceased in their efforts to get this done,” the outgoing president said in part. In subsequent on-camera remarks, Biden said he was “deeply satisfied this day has finally come, for the sake of the people of Israel and the families waiting in agony, and for the sake of the innocent people in Gaza, who suffered unimaginable devastation because of the war.” The news comes amid a brutal winter for civilians in Gaza, as well as dramatic developments across the Middle East that have dealt setbacks to Iran, an Israeli foe. “We are very happy to reach a deal today to stop the aggression against our people, but unfortunately we were unable to reach the same deal last May,” Basem Naim, a senior Hamas official, told NBC News. In a statement, Netanyahu’s office touted what it characterized as a compromise on Hamas’ part. “In light of Prime Minister Netanyahu’s firm stance, Hamas has backed down on its demand at the last minute to change the deployment of forces on” the Philadelphi Corridor, the Israeli name for the narrow strip of land between Gaza and Egypt. “However, there are still several unresolved clauses in the outline, and we hope that the details will be finalized tonight,” the prime minister’s office added. Gil Dickmann, cousin of deceased hostage Carmel Gat, told NBC News that it was “very exciting” to see that finally hostages were going to be returned. “It’s also really sad to know that Carmel could have and should have been among them, but a deal didn’t come in time and she was murdered in captivity,” he said. Adi Alexander, the father of Edan Alexander, one of the hostages held by Hamas, tells NBC News’ Lester Holt that news of the deal is “unbelievable” and “a long time coming.” Earlier, a diplomatic source in Washington told NBC News that Netanyahu was preparing to meet with his security Cabinet, where approval of the deal was expected quickly. He would then take the pact to the full Cabinet, which is also expected to approve.  Israel’s Supreme Court would have 24 hours to permit an appeal, so the earliest a ceasefire could go into effect would be Friday, the source said. The first group of hostages would come out Sunday, the person added. Israel launched its military campaign in the Palestinian enclave after Hamas’ Oct. 7 terrorist attack, in which 1,200 people were killed and 250 taken hostage. Just more than 100 were released in late November 2023 during a pause in hostilities, in exchange for 240 Palestinian prisoners. The war has shattered Gaza’s infrastructure and displaced most of its population. Health officials in the enclave say more than 46,000 Palestinians have been killed by Israeli forces — most of them civilians. The chances for a ceasefire seemed vanishingly small after many false dawns in recent months. The Biden administration had called for a final effort before the president leaves office, and many in the region and in Washington viewed Trump’s inauguration Monday as an unofficial deadline. Trump pledged last month that “all hell will break out” if Hamas doesn’t promise to release hostages by Jan. 20 and his Mideast envoy, Steve Witkoff, joined talks in the region to push for a deal. Internationally, Israel’s staunchest allies have largely stood by it during its war in Gaza, but that support has been coupled with the strongest criticism in a generation and widespread calls for a ceasefire from the United States and others. World leaders have also strongly condemned incidents of sexual violence during Hamas’ attack on Israel, as well as allegations of the sexual abuse of Palestinian prisoners by members of the Israeli military, which Israel has said it is investigating. Israel’s allies have been largely supportive of its proxy war against Iran, which the U.S. has long accused of funding Hamas and the Lebanon-based Hezbollah. Israel and Hezbollah agreed in November to halt months of deadly fighting with a ceasefire that has largely held.The scale and nature of Israel’s offensive have drawn condemnation from abroad. In November, the International Criminal Court issued an arrest warrant against Netanyahu for alleged war crimes and crimes against humanity. Amnesty International and Doctors Without Borders in December accused Israel of carrying out a genocide in Gaza. Israel-Hamas War 6 hours ago Israel and Hamas reach ceasefire deal after weeks of negotiations Israel-Hamas War 5 hours ago Trump, Biden both claim credit for Gaza ceasefire deal. Read their messages here Israel has rejected those accusations as false and antisemitic. This story first appeared on NBCNews.com. More from NBC News: Americans get warm welcome to Chinese TikTok alternative RedNote ahead of potential ban There’s been a ‘meaningful shift’ in CEO confidence since Trump’s election, says Goldman’s Solomon From Baptist churches to Buddhist temples, religious groups volunteer for fire victims