U.S. President Joe Biden’s red lines over Israel’s assault on Rafah have kept shifting, but he faces growing pressure to take a firmer stance after a deadly strike on the Palestinian city.

Despite global outrage over the attack in which 45 people were killed, the White House insisted on Tuesday that it did not believe Israel had launched the major operation that Biden has warned against.

John Kirby, the U.S. National Security Council spokesman, said that Biden had been consistent and was not "moving the stick" on what defined an all-out military offensive by key ally Israel.