The fragility of the truce between Israel and Hamas was laid bare on Saturday, after Israel accused Hamas of withholding a hostage, prompting a halt in the movement of Gazan civilians back to their homes in the north.

A U.S. backed ceasefire agreement between Lebanon and Israel will remain in effect until the middle of next month, the White House announced Sunday.

The hostages are the second set to be released since the multiphase agreement came into effect, raising hopes for a lasting end to the war.

Some troops had been expected to withdraw to allow hundreds of thousands of displaced Gazans to go home. But Israel said the hostage exchange before that step had not gone as agreed. Hamas accused Israel of stalling.

Secretary of State Antony Blinken had said the U.S. wanted a ceasefire deal in Gaza and all remaining captives released before Donald Trump takes office on Jan. 20.

Michael Levy, brother of hostage Or Levy, joins Andrea Mitchell to discuss the ceasefire agreement and the critical need for sustained international support. Levy expressed cautious optimism about the agreement,

NBC News' Raf Sanchez reports on the fragile ceasefire deal between Israel and Hamas after a crisis over the weekend threatened to unravel the peace deal with a delay from Israel in allowing displaced Palestinians to return to their homes in the north of Gaza.

Just when it seemed like that at long last peace had come to Gaza, it now looks as if the wheels might be coming off the ceasefire agreement before the ink is dry. As a reminder, Israel and Hamas approved a ceasefire-hostage agreement on 15 th January this year.