The Hamas terrorist group said Saturday that it will only release Israeli-American hostage Edan Alexander if Israel implements the existing ceasefire agreement in the Gaza Strip.

Alexander, 21, is the last living American hostage in captivity in the Gaza Strip.

A senior Hamas official told the Associated Press that long-delayed talks over the ceasefire’s second phase would need to begin the day of the release and last no longer than 50 days. Israel would also need to stop barring the entry of humanitarian aid and withdraw from a strategic corridor along Gaza’s border with Egypt.

Hamas called it an "exceptional deal" aimed at getting the truce back on track, per the official, who spoke to The AP on condition of anonymity.

AFTER TRUMP THREAT, HAMAS REFUSES TO RELEASE MORE HOSTAGES WITHOUT PHASE 2 CEASEFIRE DEAL

Hamas is also demanding the release of more Palestinian prisoners in exchange for hostages, the official said. 

Hamas on Friday agreed to release Alexander along with the bodies of four other hostages following a deal offered by mediators. He has now been held captive for 526 days as of Saturday, the Hostages and Missing Families Forum said.

It comes as talks are ongoing in Qatar to establish the next phase of the Israel-Hamas ceasefire, the first phase of which ended on March 1.

The office of Steve Witkoff, special envoy to the Middle East, and the National Security Council said in a joint statement that "President Trump has made it clear that Hamas will either release hostages immediately, or pay a severe price."

Witkoff and Eric Trager, National Security Council senior director for the Middle East and North Africa, presented a ‘bridge’ proposal to extend the ceasefire beyond Ramadan and Passover and allow time to negotiate a framework for a permanent ceasefire.

Israeli Prime Minister Benjamin Netanyahu is expected to convene his ministerial team on Saturday to receive a detailed report from negotiators and decide on the next steps for the release of the hostages.

Meanwhile, a number of rallies are expected to take place throughout Israel on Saturday to demand that all remaining 59 hostages are released, the Hostages and Missing Families Forum said. The main rallies will take place in Tel Aviv, Sha'ar HaNegev Junction, Carmei Gat and Jerusalem.

Though he spent most of his life in New Jersey, Alexander was born in Israel a few months before his parents moved to the U.S., according to the American Jewish Committee (AJC).

After graduating from high school, Alexander decided he would enlist in the Israel Defense Forces (IDF) rather than enroll in college.

On Oct. 7, Alexander, who was serving in the IDF’s Golani Brigade, an infantry unit, was patrolling near Gaza when Hamas’ attacks on Israel began. The attacks ended with 1,200 Israelis dead and 251 hostages taken, including Alexander.

Yael Alexander, Edan’s mother, recounted the day he was taken hostage in a recent interview with AJC’s "People of the Pod." Yael was in Israel in early October 2023, visiting her family and hoping to see Edan. On the morning of Oct. 7, she spoke with Edan, who said that he was seeing "terrible stuff," but he assured her that he was safe. Then he was taken hostage.

On Nov. 30, 2024, more than a year after Alexander was captured, Hamas released a video of Alexander speaking in Hebrew and Arabic. Alexander, like other hostages forced to make propaganda videos, delivered messages about Netanyahu and then-President-elect Donald Trump.

Fox News' Yael Rotem-Kuriel, Trey Yingst, Rachel Wolf and Stephen Sorace, as well as The Associated Press, contributed to this report.