WASHINGTON (AP) — President Joe Biden and Israeli Prime Minister Benjamin Netanyahu spoke Monday morning a White House official said, as Israel appeared closer to launching an offensive on the southern Gaza city of Rafah — a move staunchly opposed by the U.S. on humanitarian grounds.

A National Security Council spokesperson said Biden reiterated U.S. concerns about an invasion of Rafah — where more than 1 million civilians from other parts of Gaza are sheltering after 7 months of war sparked by Hamas' Oct. 7 attack on Israel — and said he believes reaching a cease-fire with Hamas is the best way to protect the lives of Israeli hostages held in Gaza. The officials spoke on the condition of anonymity to discuss the call before an official White House statement was released.

The call comes hours before Biden is to host King Abdullah II of Jordan for a private lunch meeting at the White House on Monday.

On Sunday, Netanyahu rejected international pressure to halt the war in Gaza in a fiery speech marking the country’s annual Holocaust memorial day, declaring: “If Israel is forced to stand alone, Israel will stand alone.”

“I say to the leaders of the world: No amount of pressure, no decision by any international forum will stop Israel from defending itself,” he said, speaking in English. “Never again is now.”