The Biden administration told Israel to take every precaution to protect civilians after a military strike in Rafah killed dozens of Palestinians, as it faced calls from some fellow Democrats to halt military shipments to Israel.
Biden has faced increasing pressure from within his own party to scale back support for Israel, even before the airstrike on Sunday night that set tents and rickety metal shelters ablaze in a Rafah camp, killing 45 people.
Alexandria Ocasio-Cortez, a prominent Democratic lawmaker in the House of Representatives, on Monday called the strike "an indefensible atrocity", adding in a social media post that "it is long past time for the President to live up to his word and suspend military aid."
"Horrific and gut wrenching images coming out of Rafah last night," Representative Ayanna Pressley said in a social media post. "How much longer will the U.S. stand by while the Israeli military slaughters and mutilates Palestinian babies?"
Representative Rashida Tlaib, the only Palestinian-American serving in Congress, called Israeli Prime Minister Benjamin Netanyahu a "genocidal maniac".
Netanyahu on Monday said the strike was not intended to cause civilian casualties but went "tragically wrong."
The NSC spokesperson said the U.S. government was "actively engaging" with the Israeli military and others on the ground to assess what happened.
Almost half of Democratic voters disapprove of Biden's handling of the Israel-Hamas war, according to a recent poll from Reuters/Ipsos.
Weeks of campus protests about the war have added to the pressure, and wider demands for a permanent ceasefire have put Biden's reelection campaign on the defensive.