The US asked Israel for a commitment regarding how to use American weapons in Gaza - and set a deadline for an answer. If Israel does not provide a "reliable and reliable" written commitment by the set deadline - American arms shipments will be suspended.
The requirement to receive such a written commitment is part of a new policy announced by President Biden in early February. The new policy concerns every country in the world that uses American weapons, but is relevant these days mainly to Israel against the background of the war in Gaza.