Hamas released a video on Sunday showing three Israeli hostages who are still being held in captivity in Gaza.

The three hostages that appear in the video are 26-year-old Noa Argamani, 35-year-old Itai Svirsky and 53-year-old Yossi Sharabi.

The video released by Hamas called on Prime Minister Benjamin Netanyahu to end the war on Gaza.

-ABC News' Ellie Kaufman

President Joe Biden on Sunday marked 100 days since Hamas launched its deadly attacks on Israel on Oct. 7, vowing to get more of the American hostages freed.

"For 100 days, they have existed in fear for their lives, not knowing what tomorrow will bring," Biden said of the hostages held by Hamas in Gaza.

"For 100 days, their families have lived in agony, praying for the safe return of their loved ones," Biden added, saying the families have been "at the forefront of my mind."

"No one should have to endure even one day of what they have gone through, much less 100," he said.

"We will never stop working to bring Americans home," Biden pledged.

-ABC News' Fritz Farrow

As the Israel-Hamas war reached its 100th day Sunday, the Israel Defense Forces says it's goals "will take a long time" to achieve.

"To achieve real results, we must continue to operate in enemy territory, not to allow extortion attempts for a cease-fire," IDF Lt. Gen. Herzi Halevi said in a televised address Saturday.

"We must continue applying pressure and that is exactly what we are doing," he said. "[Our] goals are complex to achieve and will take a long time. To dismantle Hamas, patience is both necessary and essential."

The IDF also said it's now moving to intensify its operations in southern Gaza, where it believes Hamas' leadership is hiding.

-ABC News' Patrick Reevell

The U.S. ambassador to Israel, Jack Lew, addressed a rally in Tel Aviv on Sunday demanding the immediate return of the hostages still being held by Hamas.

"One day is too many -- 100 days is unfathomable," Lew told the crowd. "My heart aches for all who have been affected by Oct. 7 and I stand in solidarity, as does the United States, with the families of the hostages. I add my voice to theirs to say: Bring them home now."

Tens of thousands of Israelis have rallied over the last 24 hours to demand the return of the hostages on the 100th day of their captivity.

-ABC News’ Patrick Reevell

Speaking from a podium in Tel Aviv, U.S. Secretary of State Antony Blinken announced that he and Israeli officials had agreed on a plan to carry out a United Nations-led mission in Gaza that will pave the way for displaced Palestinians to return to their homes in the north -- a significant step toward restoring a sense of normalcy in the enclave.

"As Israel's campaign moves to a lower intensity phase in northern Gaza, and as the IDF scales down its forces there, we agreed today on a plan for the U.N. to carry out an assessment mission. It will determine what needs to be done to allow displaced Palestinians to return safely to homes in the north," he said.

"Now, this is not going to happen overnight. There are serious security, infrastructure and humanitarian challenges," Blinken cautioned, later describing traps and explosives left by Hamas as a hinderance. "But the mission will start a process that evaluates these obstacles and how they can be overcome."

Blinken stressed the U.S. focus on humanitarian issues stemming from the conflict, but he also slammed a case brought by South Africa before the U.N.’s highest legal body, the International Court of Justice, which accuses Israel of carrying out genocide in Gaza, declaring that it "distracts the world" from vital efforts.

"Moreover, the charge of genocide is meritless," Blinken asserted. "It's particularly galling given that those who are attacking Israel -- Hamas, Hezbollah, the Houthis, as well as their supporter, Iran -- continue to openly call for the annihilation of Israel and the mass murder of Jews."

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Secretary Blinken delivers remarks following high-level meeting in Israel

-ABC News' Shannon K. Crawford