The US last week paused a bomb shipment for Israel over concerns it was going ahead with a major ground operation in the southern Gaza city of Rafah, a senior US administration official said.
The shipment consisted of 1,800 2,000lb (907kg) bombs and 1,700 500lb bombs, the official told the BBC.
Israel has not "fully addressed" US concerns over humanitarian needs of civilians in Rafah, the official said.
An Israeli military official appeared to play down the US move.