President Joe Biden held urgent talks with Prime Minister Benjamin Netanyahu on Monday after Israel defied repeated US warnings and told Palestinians to evacuate part of the southern Gaza city of Rafah ahead of an offensive.

The call came as Biden mounts a diplomatic offensive to get ceasefire talks between Israel and Hamas back on track, with Jordan's King Abdullah II due at the White House for lunch on Monday.

Biden told Netanyahu in April that invading Rafah would be a "mistake," and Washington has said it does not support an offensive without a credible plan to protect some 1.2 million civilians sheltering there.

The White House confirmed that "President Biden spoke today with Prime Minister Netanyahu," and said it would release a readout with details of the call soon.

Biden did not respond to shouted questions and walked straight to the Oval Office from his helicopter, Marine One, after arriving back at the White House from a weekend at his family home in Wilmington, Delaware.

A spokesman for the US National Security Council, announcing earlier that the call would take place, said "we have made our views clear on a major ground invasion of Rafah to the Israeli government."

"We continue to believe that a hostage deal is the best way to preserve the lives of the hostages, and avoid an invasion of Rafah, where more than a million people are sheltering," the spokesman said.

"Those talks are ongoing now."

Biden is under growing domestic pressure about the war in Gaza in an election year, with pro-Palestinian protests roiling US university campuses in recent weeks.

New York's prestigious Columbia University, which has been at the heart of the protests, said on Monday it had canceled the main graduation ceremony for students next week. (AFP)