The US State Department says it has "credible reports" that Hamas is planning an "imminent" attack on civilians in Gaza, which it says would violate the ceasefire agreement.
A statement released on Saturday said a planned attack against Palestinians would be a "direct and grave" violation of the ceasefire agreement and "undermine the significant progress achieved through mediation efforts".
The state department did not not provide further details on the attack and it is unclear what reports it was citing.
The first phase of the ceasefire deal between Hamas and Israel is currently in progress - all living hostages have been released and bodies of the deceased are still being returned to Israel.
Also part of the agreement, Israel freed 250 Palestinian prisoners in its jails and 1,718 detainees from Gaza.
