Netanyahu signals openness to Trump's Gaza ceasefire plan: Sources

French President Emmanuel Macron officially called for Palestinian statehood at the United Nations General Assembly opening session Monday afternoon, joining several other countries this week in calling for statehood, despite condemnations from the United States and the Israeli government.

"The time has come. This is why true to the historic, historic commitment of my country to the Middle East, to peace between the Israelis and the Palestinians. This is why I declare that today France recognizes the state of Palestine," Macron said in the Assembly Hall of the U.N. headquarters.

Several delegates from Palestine -- and many others in the room -- jumped to their feet and applauded Macron for an extended time.

"We've gathered here because the time has come," Macron said. "The time has come to free the 48 hostages detained by Hamas. The time has come to stop war, the bombing in Gaza, the massacres and the fleeing people. The time has come because there's a pressing urgency everywhere. The time for peace has come because we're just a few moments away from no longer being able to seize peace. This is why we have gathered here today. Some might say it's too late. Others might say it's too early. But one thing is certain: We can no longer wait."

His proclamation came a day after the United Kingdom, Canada, Australia and Portugal also released statements declaring their support for a Palestinian state.

Palestinian President Mahmoud Abbas -- who joined the meeting virtually because the U.S. did not grant him a visa -- was seen applauding throughout the speech.

-ABC News' Mariam Khan

The Israel Defense Forces on Monday said that its troops killed "approximately 15" fighters in Gaza City amid Israel’s operation to take control of the Gaza Strip’s largest urban area.

The IDF operation in Gaza City was launched last week, with two divisions -- the 162nd and 98th divisions -- pressing into the "heart" of the city, according to the IDF. A third division, the 36th, was deployed to join the operation over the weekend.

The IDF said artillery units attacked a structure from which Hamas fighters launched two rockets towards Israel on Sunday.

The IDF also said that its warplanes operating over Gaza City struck what it said was a factory producing military equipment and a group of fighters nearby.

The IDF added that additional strikes took place in Khan Younis and Rafah in the southern part of the strip.

Israeli Prime Minister Benjamin Netanyahu was unequivocal in his rejection of the U.K., Canada and Australia recognizing a Palestinian state, saying in a statement Sunday "there will be no Palestinian state."

"It will not happen. A Palestinian state will not be established west of the Jordan River," the statement repeated.

Netanyahu also emphasized his government's expansion of West Bank settlements and says "we will continue on this path."

In a separate statement, the Israeli Foreign Ministry said the recognition "will push the desired peace further away," and that "if the countries that signed this declaration truly wish to stabilize the region, they should focus on pressuring Hamas to release the hostages and to disarm immediately."

A statement from the Hostage Families Forum said it "condemns" the announcements, saying the recognition "[turns] a blind eye to the fact that 48 hostages remain in Hamas captivity."

"We call on all nations to act responsibly and ensure that any 'day after' discussions occur only after our loved ones are brought home," the statement said, in part.

-ABC News' Jordana Miller