An Israeli scheme to move hundreds of thousands of already uprooted Palestinians to a so-called "humanitarian city" in Gaza has led politicians to spar with the defence establishment, but officials say a practical plan has yet to be crafted.

EU foreign policy chief Kaja Kallas on Tuesday said the bloc was leaving the door open to action against Israel over the war in Gaza if the humanitarian situation does not improve. Kallas has put forward 10 potential options after Israel was found to have breached a cooperation deal between the two sides on human rights grounds.