Israel began the first stage of a planned assault on Gaza City on Wednesday, calling up tens of thousands of reservists as Prime Minister Benjamin Netanyahu accelerated plans to seize what officials described as Hamas's last major stronghold.

"We have begun the preliminary operations and the first stages of the attack on Gaza City, and already now IDF forces are holding the outskirts of Gaza City," Brigadier General Effie Defrin, Israel's military spokesman, told reporters. He added: "We will deepen the attack on Hamas in Gaza City, a stronghold of governmental and military terror for the terrorist organization."

Defense Minister Israel Katz authorized the plan, which includes mobilizing 60,000 reservists and extending the service of 20,000 already deployed. A military official said Wednesday that reserve soldiers would not report until September, giving international mediators a narrow window to negotiate a ceasefire.

Netanyahu's office said the timeline for defeating Hamas and "seizing control of the last terrorist strongholds" was being shortened. In a statement, the prime minister praised reservists and soldiers, declaring, "Together we will win."

The announcement came as Egyptian Foreign Minister Badr Abdelatty confirmed Hamas had agreed to a 60-day ceasefire proposal advanced by President Donald Trump's envoy, Steve Witkoff. "The ball is now in Israel's court," Abdelatty told NBC News. "We would like a positive response from them as soon as possible in order to deal with the disastrous situation in Gaza, especially the starvation and the killing of civilians."

Israel has so far signaled it intends to press forward. Netanyahu's office pointed to Hamas being "under immense pressure" and did not confirm whether a formal response would be delivered to mediators this week.

Meanwhile, Israel's military said it clashed Wednesday with more than 15 Hamas militants who emerged from tunnel shafts near Khan Younis. According to an Israeli official, one soldier was severely wounded and two others lightly injured. Hamas's Al-Qassam Brigades said a fighter detonated himself among Israeli troops during the encounter.

Rights groups warned that another mass displacement could worsen the humanitarian crisis. "Further displacement and an intensification in hostilities risk worsening an already catastrophic situation," the International Committee of the Red Cross said. New satellite imagery indicated that tent camps south of Gaza City had emptied in recent days as families fled.

Mohammed Abu Sharia, a Gaza City resident, told NBC News his family had been forced to leave again after months of displacement. "There is no safe place, neither in the north nor the south," he said. "My concern is to save the family's life, as we are suffering from food shortages and the lack of any belongings with us."

The conflict, which began with the Hamas-led Oct. 7, 2023, attack that killed about 1,200 people in Israel and took 251 hostages, has left more than 62,000 Palestinians dead, according to Gaza health officials. Most of the victims, they said, have been women and children.