US national security adviser Jake Sullivan has warned the Israeli government against “smashing into Rafah” as the Biden administration underlines its opposition to the planned assault on one of Gaza’s biggest cities.

The US was continuing to urge the Israeli government of Prime Minister Benjamin Netanyahu to protect civilians and find a path for a long-term peace, Sullivan said. But an assault on the southern Gaza city was not necessary in the effort to “crush Hamas”, he added.

“[Biden] believes there is a path to do that, and that path does not lie in smashing into Rafah, where there are 1.3mn people, in the absence of a credible plan to deal with the population there,” Sullivan said on Tuesday. “We have not seen a credible plan to protect those civilians.”