Senior U.S. officials reiterated their concerns about an Israel ground operation into Rafah during a meeting between the two countries on Thursday.

Israeli leaders argue they have to carry out full-scale military operations in the southern Gaza city of Rafah to defeat the four Hamas battalions that remain intact, but it’s also where more than a million Palestinians have fled during the course of the war. The United States does not support such operations without Israel accounting for the significant civilian population in the city, and Israel has yet to detail publicly how it plans to ensure their safety.