"In the absence of a plan for the day after, there won't be a day after. And this is where we need to go, and (what) we need to get, as quickly as possible," Blinken told reporters on a visit to Moldova.

Such a plan would ensure that Israel is not in control of Gaza's security in the long term, he said.

"If it is, it will simply have an enduring insurgency on his hands for as far as one can see into the future," Blinken said.

"Or if not, Hamas will be left in charge, which is not acceptable. Or if not, we'll have chaos, lawlessness and a vacuum that eventually will be filled again by Hamas or maybe something, if it's possible to imagine, even worse -- jihadists."

Israeli National Security Adviser Tzachi Hanegbi said earlier that the military would need "another seven months" to "consolidate our success" against Hamas.

President Joe Biden has supported Israel's response to the October 7 Hamas attack but has called on Israel to do more to protect civilians and has faced growing pressure as he seeks re-election in November.

Blinken said that a weekend Israeli strike that ignited an inferno in a displacement camp outside Rafah, killing 45 people according to Palestinian officials, was "horrific".

"Anyone who has seen the images cannot be deeply affected by them, just on a basic human level," Blinken said.

"We have been very clear with Israel on the imperative -- in this instance as in other instances -- to immediately investigate and determine exactly what happened and why it happened, and if accountability is necessary to make sure that there is accountability," Blinken said.

He said he could not verify a report that US weapons were used in the attack.

Hamas launched an unprecedented attack on October 7 that resulted in the deaths of 1,189 people, mostly civilians, according to an AFP tally based on Israeli official figures.

Militants also took 252 hostages, 121 of whom remain in Gaza, including 37 the army says are dead.

Israel's retaliatory offensive has killed at least 36,171 people in Gaza, mostly civilians, according to the territory's health ministry.