The Israeli military signaled that it has wrapped up major combat in northern Gaza, saying it has completed dismantling Hamas’ military infrastructure there, as the war against the terrorist group entered its fourth month Sunday.

The military did not address troop deployments in northern Gaza going forward. Its spokesman, Rear Admiral Daniel Hagari, said late Saturday that forces would “continue to deepen the achievement” there, strengthen defenses along the Israel-Gaza border fence and focus on the central and southern parts of the territory.

The announcement came ahead of a visit to Israel by Secretary of State Blinken. Biden administration officials, including Mr. Blinken, have repeatedly urged Israel to wind down its air and ground offensive in Gaza and shift to more targeted attacks against Hamas leaders to prevent harm to Palestinian civilians.

In recent weeks, Israel had already been scaling back its military assault in northern Gaza and pressing its offensive in the territory’s south, where most of Gaza’s 2.3 million Palestinians are being squeezed into smaller areas.

Prime Minister Netanyahu on Sunday again insisted the war will not end until the objectives of eliminating Hamas, getting Israel’s hostages returned and ensuring that Gaza won’t be a threat to Israel are met.

“I say this to both our enemies and our friends,” he told his Cabinet. “This is our responsibility and this is the obligation of all of us.”

Israeli forces were pushing deeper into the central city of Deir al-Balah, where on Saturday residents in several neighborhoods were warned in flyers dropped over the city that they must evacuate their homes.

The international medical charity Doctors Without Borders, known by the acronym MSF, said it was evacuating its medical staff and their families from Deir al-Balah’s Al Aqsa Martyrs’ Hospital because of the growing danger.

“The situation became so dangerous that some staff living in the neighboring areas were not able to leave their houses because of the constant threats of drones and snipers,” said Carolina Lopez, the group’s emergency coordinator at the hospital.

She said a bullet penetrated a wall of the hospital’s intensive care unit on Friday, and that “drone attacks and sniper fire were just a few hundred meters from the hospital” over the past couple of days.

Mr. Hagari, the military spokesman, said the scattered fighting in northern Gaza was to be expected, along with rockets sporadically being launched from there toward Israel. He said Hamas no longer operates in an organized manner in the area, but that militants “without a framework and without commanders” are still present. The military has said it has killed more than 8,000 Hamas fighters.

Mr. Hagari said Israeli forces would act differently in the south than they had in northern Gaza, where heavy bombardment and ground combat leveled entire neighborhoods.

He said the urban areas currently being targeted by the military are packed with gunmen and that “an underground city of sprawling tunnels” was discovered underneath Khan Younis. He said the military is “applying the lessons we learned,” but did not elaborate. Echoing Israeli political leaders, he said the fighting “will continue throughout 2024.”

His comments about changing the way the forces are fighting appeared to be a nod to Mr. Blinken, who is on his fourth Mideast trip in three months.

In addition to appeals for scaling back high-intensity combat, Mr. Blinken has called for more aid to reach Gaza and urged Israel’s leaders to come up with a vision for post-war Gaza.

The Biden administration and Mr. Netanyahu remain far apart on who should run the territory after the war, with the Israeli leader repeatedly rejecting the Washington-floated idea of having a reformed Palestinian Authority, an autonomy government in parts of Judea and Samaria, eventually administer Gaza.

In a further complication of Mr. Blinken’s mission, a new escalation of cross-border fighting between Israel and Lebanon’s Hezbollah has put strains on an American push to prevent a regional conflagration. Saturday’s fighting was described by Hezbollah as an “initial response” to the targeted killing of a top Hamas leader in a Hezbollah stronghold of the Lebanese capital of Beirut last week. The strike was presumed to have been carried out by Israel.