U.S. Secretary of State Antony Blinken was due to meet Israeli leaders on Tuesday in his quest to prevent the Gaza conflict from growing into a regional conflagration, as the Israeli military said its fight against Hamas would continue all year.

Blinken arrived in Tel Aviv late on Monday to brief Israeli officials on his two days of talks with Arab leaders on ending the war, which was triggered by Hamas militants' attack on Oct. 7 that by Israeli tallies killed about 1,200 people.

He also said he would press Israeli Prime Minister Benjamin Netanyahu's government “on the absolute imperative to do more to protect civilians and to do more to make sure that humanitarian assistance is getting into the hands of those who need it”.

The Israeli offensive has killed more than 23,000 Palestinians, destroyed much of Gaza and displaced most of the population of 2.3 million, creating a worsening humanitarian crisis.

In the latest sign that the war may be spreading, Israel killed a top commander of Hamas’ ally Hezbollah in south Lebanon on Monday, sources familiar with the group's operations said.

Sources with direct knowledge of the matter told Reuters Israel is also carrying out an unprecedented wave of deadly strikes in Syria targeting cargo trucks, infrastructure and people involved in Iran's weapons lifeline to its proxies in the region.

Israeli Defence Minister Yoav Gallant told the Wall Street Journal his country was determined to end Hamas’ rule of Gaza and deter other Iran-backed adversaries.

But Israel has come under growing pressure from the United States, its closest ally, and Arab leaders to scale back the assault.

U.S. President Joe Biden, confronted on Monday by protesters shouting “ceasefire now” while visiting an historic Black church in South Carolina, said he had been “quietly” working to encourage Israel to ease its attacks and “significantly get out of Gaza”.

Israeli officials have said the operation is entering a new phase of more targeted warfare, but there was no respite in the fighting on Monday.

Rear Admiral Daniel Hagari, an Israeli military spokesman, said a “different mix of forces” was pursuing holdout Hamas fighters in the north as “intense operational activity” focused on central Gaza and around the southern city of Khan Younis.

“Handling tough battles in both the centre and south,” Hagari said. “The fighting will continue through 2024.”

Israel must allow displaced Palestinian civilians to return to their homes in Gaza, Blinken said in response to calls by right-wing members of Israel's ruling coalition for them to move elsewhere.

Israeli leaders will tell Blinken that they will not allow Palestinians from northern Gaza to return if Hamas refuses to free more of the Israeli hostages it seized on Oct. 7, Axios reported, quoting two senior Israeli officials. Israel says Hamas still holds more than 100 hostages of the 240 seized on Oct. 7.

On Monday, Israeli forces bombarded the eastern part of Khan Younis and the central Gaza Strip amid ground clashes, residents said. Israel said four soldiers were killed in Gaza on Monday, bringing its total war losses there to 182.

The Israeli military also said it had bombed an arms cache, uncovered a tunnel shaft in central Gaza and killed at least 10 militant fighters in Khan Younis.

Hamas' military wing, the Al-Qassam Brigades, said its fighters fired missiles at Tel Aviv in response to what it called the "Zionist massacres against civilians".

Blinken flew to Tel Aviv after talks in the United Arab Emirates and Saudi Arabia to try to chart a way out of the bloodiest chapter ever of the decades-long Israel-Palestinian conflict. It is his fourth mission to the region since October.

Speaking to reporters after meeting Saudi Arabian Crown Prince Mohammed bin Salman in the Saudi oasis town of Al Ula, Blinken said he still found support among Arab leaders for Israel's goal of normalising relations.

But that will "require that the conflict end in Gaza" and "a practical pathway to a Palestinian state," said Blinken, who held talks in Jordan and Qatar on Sunday.

The Saudi crown prince, the kingdom's de facto ruler, stressed the importance of stopping the hostilities and forging a path to peace, Saudi state news agency SPA reported.Jordan's King Abdullah said on Monday that "indiscriminate aggression" and shelling could never bring peace or security.

In remarks at the Kigali Genocide Memorial in Rwanda, he said: "More children have died in Gaza than in all other conflicts around the world this past year. Of those who have survived, many have lost one or both parents, an entire generation of orphans."

Nearly all of Gaza's residents have fled their homes at least once and many remain on the move, often sheltering in makeshift tents or under tarpaulins.

For Aziza Abbas, 57, camped close to the southern border with Egypt, there was nowhere else to go after what she said was bombing around a school in which she had taken shelter after leaving her home in the north.

"They may kill us here, it doesn't matter to them," she told Reuters, saying she did not want to leave Gaza for Egypt, which has closed the border, fearing an exodus.