US president Joe Biden underscored the need to sustain "a continuous flow" of humanitarian assistance into Gaza in call with Israeli prime minister Benjamin Netanyahu on Monday, the White House said.
Mr Biden also "welcomed the release of two additional hostages from Gaza earlier today, and reaffirmed his commitment to ongoing efforts to secure the release of all the remaining hostages taken by Hamas," the White House added.
He also updated the prime minister on "US support for Israel and ongoing efforts at regional deterrence, to include new US military deployments," according to the White House.
The US has told Iranian-backed Hezbollah in Lebanon and other groups not to join the fight.
Israel has frequently traded fire with Hezbollah and Israeli warplanes have hit targets in the occupied West Bank, Syria and Lebanon in recent days.
The US advised Israeli officials that delaying a ground offensive would give Washington more time to work with regional mediators on securing the release of more hostages taken by Hamas during its deadly incursion, according to a US official.
Israeli defence minister Yoav Gallant told troops near Gaza to keep preparing for an offensive “because it will come”.
He said it will be a combined offensive from air, land and sea but did not give a timeframe.
Tanks and troops have been massed at the Gaza border, and Israel says it has stepped up airstrikes to reduce the risk to troops in the next stages.
A ground excursion is likely to dramatically increase casualties in what is already the deadliest by far of five wars fought between Israel and Hamas since the militants seized power in Gaza in 2007.
More than 1,400 people in Israel have been killed, mostly civilians during the initial Hamas attack.
At least 222 people were captured and taken back to Gaza, including foreigners, the military said on Monday, updating a previous figure. - Additional reporting from Associated Press
