Governments around the world have voiced their concern at the Israeli military's plan to conduct ground operations in Rafah in the southern Gaza Strip.
The White House announced on Sunday that US President Joe Biden spoke by phone with Israeli Prime Minister Benjamin Netanyahu.
It said Biden reaffirmed his view that the operations in Rafah "should not proceed without a credible and executable plan for ensuring the safety and support for the more than one million people sheltering there."
France's foreign ministry on Sunday issued a statement saying that a large-scale Israeli offensive in Rafah would create a catastrophic humanitarian situation of a new and unjustifiable dimension.
A foreign ministry spokesperson of Egypt, which acts as a mediator for negotiations between Israel and Hamas, also issued a statement on Sunday.
It called for concerted international and regional efforts to prevent the targeting of Rafah, which now shelters about 1.4 million displaced Palestinians.
Netanyahu has stressed the need for an intensive attack on Rafah, where Israel says a Hamas stronghold is located.
In an interview with ABC News aired on Sunday, he said arguing that Israeli forces should not enter Rafah is basically saying "lose the war."
A senior Hamas member has warned that hostage releases would not be negotiable if attacks on Rafah intensify.
On Monday, Reuters news agency reported that Israeli strikes on Rafah killed at least 37 people and wounded dozens of others.
Health authorities in Gaza say 28,176 people have been killed in the enclave since fighting between Israeli forces and Hamas broke out last October.