WASHINGTON, Dec 15, 2023 (bss/AFP) - The United States told Israel on Wednesday to scale down its war on Hamas in the "near future," with President Joe Biden urging it to take more care to save civilian lives in Gaza.

US National Security Advisor Jake Sullivan made the push during talks in Tel Aviv with Prime Minister Benjamin Netanyahu and other senior officials, discussing the war Israel launched after the October 7 attacks.

Washington has strongly backed Israel's right to defend itself, but mounting civilian casualties in the Palestinian territory have caused a growing rift between the close allies.

"I want them to be focused on how to save civilian lives -- not stop going after Hamas, but be more careful," Biden told reporters after an event at a medical research center near Washington.

The White House said earlier that Sullivan, Biden's top national security aide, had pushed Israel on the timing of the war after Israel's defense minister told him that the conflict would last several more months.

Sullivan "did talk about possible transitioning from what we would call high-intensity operations, which is what we're seeing them do now, to lower-intensity operations sometime in the near future," spokesman John Kirby said.

"But I don't want to put a timestamp on it."

Kirby said that Washington was "not dictating terms" to Israel but that Sullivan had asked "hard questions" about the course of the offensive, while still backing the country.

"I think we all want it to end as soon as possible," Kirby told reporters, adding that the war "could end today" if Hamas backed down, but "that doesn't look likely right now."

- 'Destroy them' -

The White House later said Sullivan had discussed "setting conditions for shifts over time from high-intensity clearing operations to lower-intensity surgical operations against Hamas remnants."

Israeli Defense Minister Yoav Gallant had warned Sullivan that Israel's fight with Hamas "will require a period of time -- it will last more than several months, but we will win and we will destroy them."

A senior US official refused to discuss in detail a timeline after US media reported Washington had urged Israel to end the first phase by the end of the year.

Sullivan on Friday will head to the Israeli-occupied West Bank city of Ramallah for talks with Palestinian Authority leaders, the official said.

The US official also added that Hamas leader Yahya Sinwar's "days are numbered"

"He has American blood on his hands," the official said, speaking on condition of anonymity. "It doesn't matter how long, justice will be served."

Sullivan visited Saudi Arabia for on Wednesday for talks with the country's de facto ruler, Crown Prince Mohammed bin Salman, the White House said.

Biden issued his strongest criticism yet of Israel on Tuesday, warning that the country risked losing global support over its "indiscriminate bombing" of Gaza.

A defiant Netanyahu has however vowed to carry on "until victory" and Foreign Minister Eli Cohen said the war against Hamas would continue "with or without international support".

The war, now in its third month, began after the Palestinian group's unprecedented October 7 attacks on Israel that Israeli officials say killed about 1,200 people, mostly civilians.

In response, Israel vowed to destroy Hamas and launched an unrelenting military offensive that has left swathes of Gaza in ruins. The health ministry in the Hamas-run territory said 18,787 people have been killed, mostly women and children.