The US has proposed a draft resolution at the UN Security Council which calls for a temporary ceasefire in Gaza.
It has also warned Israel against invading the overcrowded city of Rafah.
The US has previously avoided the word “ceasefire” during UN votes on the war, but President Joe Biden has made similar comments.
However, the US plans to veto another draft resolution – from Algeria – which calls for an immediate humanitarian ceasefire.
More than a million displaced Palestinians, who represent about half of Gaza’s population, are crammed into Rafah after being forced to seek shelter there.
The southern city, which borders Egypt, was home to only 250,000 people before the war.
Many of the displaced are living in makeshift shelters or tents in squalid conditions, with scarce access to safe drinking water or food.
The UN has issued its own warning that a planned Israeli offensive in the city could lead to a “slaughter”.
Israel launched its operations in Gaza following an attack by Hamas gunmen on southern Israel on 7 October, during which about 1,200 people were killed and more than 240 others taken hostage.