The White House said a reported Hamas attack on Israeli soldiers would be a "barbaric violation" of the ceasefire agreement.
US Secretary of State John Kerry has spoken to Israeli Prime Minister Benjamin Netanyahu, a White House spokesman Josh Earnest told CNN.
There have been two days of quiet in Gaza. No rockets or missiles, no more destroyed houses, no more ambulance sirens screaming.
A three-year-old girl has been rescued from Gaza and brought to London for life-saving heart surgery.
A small team of NHS doctors and surgeons is travel to Gaza to set up facilities and establish how best to use specialists and equipment.