Fifteen Israeli soldiers were killed in combat in the Gaza Strip over the weekend, the Israeli military said Sunday.

Israeli Prime Minister Benjamin Netanyahu called the fatalities a "very heavy price."

This weekend’s fatalities bring the total number of Israeli soldiers killed since the ground offensive began to 153, the Israel Defense Forces said.

Israel is "deepening the war" in Gaza, and Israeli soldiers "will continue to fight until the complete victory over Hamas," Israeli Prime Minister Benjamin Netanyahu said in an address Sunday.

"This is the only way to return our abductees, eliminate Hamas and ensure that Gaza will no longer be a threat to Israel," Netanyahu said. "It will take time, but we are united -- the fighters, the people and the government."

President Joe Biden said he did not ask for a cease-fire during a call earlier Saturday with Israeli Prime Minister Benjamin Netanyahu.

"I had a long talk with Netanyahu today. It was a private conversation," he told reporters while leaving the White House for Christmas at Camp David.

He later said, "I did not ask for a cease-fire."

The leaders discussed Israel's military operation in Gaza, the humanitarian crisis in Gaza and securing the release of the remaining hostages, according to a readout of the call released by the White House. The two agreed to remain in "regular consultation," the readout stated.

Biden also did not respond to questions about a new Wall Street Journal report that in the days after the Oct. 7 attack he convinced Netanyahu against a preemptive strike on Hezbollah forces in Lebanon.

ABC News has not confirmed the report.

-ABC News' Lauren Peller and Jay O'Brien

Gadi Hagi, a 73-year-old American-Israeli hostage and member of Kibbutz Nir Oz, has been confirmed dead, the kibbutz said.

Hagi was killed on Oct. 7 at the kibbutz and his body was taken to Gaza where it's still being held, according to a kibbutz spokesperson.

Hagi’s wife, 70-year-old Judy Weinstein, is wounded and still being held hostage, the kibbutz said.

Hagi and his wife were shot and kidnapped on Oct. 7, according to the Hostage Center.

"Gadi was a man full of humor who knew how to make those around him laugh," the Hostage Center said in a statement. "A musician at heart, a gifted flautist, he played in the IDF Orchestra and was involved with music his whole life."

Hagi was a father of four and a grandfather of seven.

Hagi reportedly has ties to New York.

"May Gadi's memory be a blessing," New York Gov. Kathy Hochul wrote on social media. "There are still many hostages -- including many with New York connections -- being held in Hamas captivity."

President Joe Biden said he was "heartbroken by the news."

"We continue to pray for the well-being and safe return of his wife, Judy," Biden said in a statement. "We are praying for their four children, seven grandchildren, and other loved ones and are grieving this tragic news with them."

Biden said Hagi's daughter joined, via phone, his meeting last week with families of hostages.

"Those families bravely shared with me the harrowing ordeal that they have endured over the past months as they await news of their loved ones," Biden said. "I reaffirm the pledge we have made to all the families of those still held hostage: we will not stop working to bring them home."