Live updates: Follow the latest news on Israel-Gaza
Dozens of Democrats in the US House of Representatives have written to President Joe Biden to warn him that an Israeli ground offensive into Rafah could breach his requirements for US military aid to be used under international law.
More than one million people are sheltering in the southern Gaza city after much of the rest of the enclave has been flattened by Israeli bombs. Israel says it wants to move on Rafah to root out remaining Hamas fighters.
Thirty-seven members of Congress expressed a “deep sense of urgency and alarm about the potentially devastating consequences to innocent civilians of an Israeli military ground invasion of Rafah”.
On February 8, Mr Biden issued a national security memorandum that requires countries receiving American weapons to abide by US standards and international laws of war.
Tuesday's letter, first reported by Axios, states that if Israel were to further invade Rafah, it “would likely contravene the principles” of the memo and would worsen the “already dreadful” conditions for civilians there.
In other words, by shipping more arms to Israel, Mr Biden would be breaking his own rule.
“We urge you to use every tool at your disposal to ensure that the norms of American and international law are observed throughout this conflict and that all recipients of US aid are held accountable,” the letter states.
On Wednesday, The Washington Post reported that the US has approved more than 100 military sales to Israel since it declared war on Hamas following the militants' attacks of October 7.
The weapons delivered include thousands of precision-guided munitions, small diameter bombs, bunker busters, small arms and other lethal aid, the Post reported US officials as having told lawmakers in a recent classified briefing.
Those deliveries were made even as the Biden administration publicly upbraided Israel for not doing enough to protect civilians in its war on Gaza, where more than 30,700 people have been killed, according to local health authorities.
Last month, a group of progressive Democratic senators warned Mr Biden against a possible upcoming weapons transfer to Israel without commitments from Benjamin Netanyahu, stating they had “no confidence” that the Israeli Prime Minister could protect civilians in a Rafah operation.
Asked about the letter, White House Press Secretary Karine Jean-Pierre reiterated US support for Israel's right to defend itself against Hamas.
“We also continue to urge Israel to do everything possible to avoid civilian casualties even as Hamas has embedded itself” among civilians, she said.
Women in Gaza during the conflict – in pictures
