WASHINGTON

Additional US assistance for the Israeli military is "on its way," President Joe Biden told Israeli Prime Minister Benjamin Netanyahu on Sunday amid renewed tensions with Palestine.

Fighting between Israel and Palestinian resistance group Hamas continued for the second day on Sunday as the former declared a state of war.

Hamas launched the biggest attack on Israel in decades on Saturday, firing thousands of rockets and capturing many Israelis. It said the action was in response to storming of the Al-Aqsa Mosque and increased settler violence.

In retaliation, the Israeli army initiated its own operation against Hamas in the Gaza Strip, and at least 700 Israelis and 370 Palestinians are reported dead.

The US president, who also spoke to Netanyahu on Saturday, updated him on the intensive diplomatic engagement undertaken by the US over the last 24 hours in support of Israel, the White House said in a statement.

"The President also conveyed that additional assistance for the Israeli Defense Forces is now on its way to Israel with more to follow over the coming days," it said.

Earlier in the day, Biden threw his support behind Tel Aviv, saying: "The US stands with Israel. We will not ever fail to have their back."

The two leaders also "discussed the taking of hostages by Hamas terrorists, including entire families, the elderly, and young children" and Biden said "all countries must stand united in the face of such brutal atrocities."

"The leaders also discussed ongoing efforts to ensure that no enemies of Israel believe they can or should seek advantage from the current situation," said the statement.

Meanwhile, Pentagon chief announced deployment of navy ships and military aircraft in proximity to Israel as a demonstration of support.

In a statement, Defense Secretary Lloyd Austin said he directed several steps to strengthen Pentagon's posture in the region to bolster regional deterrence efforts.

"I have directed the movement of the USS Gerald R. Ford Carrier Strike Group to the Eastern Mediterranean," said Austin.

"This includes the U.S. Navy aircraft carrier USS Gerald R. Ford (CVN-78), the Ticonderoga-class guided missile cruiser USS Normandy (CG 60), as well as the Arleigh-Burke-class guided missile destroyers USS Thomas Hudner (DDG 116), USS Ramage (DDG 61), USS Carney (DDG 64), and USS Roosevelt (DDG 80). We have also taken steps to augment U.S. Air Force F-35, F-15, F-16, and A-10 fighter aircraft squadrons in the region. The U.S. maintains ready forces globally to further reinforce this deterrence posture if required," he added.

Citing officials familiar with the planning, NBC News said the deployments may commence promptly, although full positioning of assets, particularly the ships, is anticipated to take several days.

The US is also actively formulating strategies for a potential non-combatant evacuation aimed at assisting Americans in departing Israel, said the report.

White House earlier said Biden and Vice President Kamala Harris' national security teams were engaged with Israelis and counterparts throughout the region.