An all-out Israeli offensive on the Gaza city of Rafah would provoke “anarchy” without eliminating Hamas, US Secretary of State Antony Blinken said on Sunday, as Washington stepped up a pressure campaign against such an assault, AFP reports.

Separately, US National Security Advisor Jake Sullivan emphasized Washington’s concerns about an offensive in a call with his Israeli counterpart, Tzachi Hanegbi.

“Mr. Sullivan reiterated President Biden’s longstanding concerns over the potential for a major military ground operation into Rafah, where over one million people have taken shelter,” a White House readout of the phone call said.

It said Hanegbi “confirmed that Israel is taking US concerns into account,” but did not elaborate.

But Blinken, when asked on CBS‘s “Face the Nation” whether the US concurred with Prime Minister Benjamin Netanyahu’s statement that Israeli forces had killed more civilians than Hamas militants since the conflict began, replied simply, “Yes, we do.”

Blinken said a full-scale invasion could come “potentially at an incredibly high cost” and that even a massive assault on Rafah was unlikely to end the Hamas threat.

“Israel’s on the trajectory, potentially, to inherit an insurgency with many armed Hamas left, or if it leaves, a vacuum filled by chaos, filled by anarchy and probably refilled by Hamas,” he said.

Blinken also confirmed that the hold President Joe Biden has placed on weapons to Israel — as the US continues pressing it to better protect civilians and avoid an all-out invasion of Rafah — is limited to 3,500 “high-capacity” bombs.