Nancy Pelosi, the former US House of Representatives Speaker, signed a letter on Friday from dozens of Democrats in Congress to President Joe Biden demanding a halt to arms transfers to Israel.
The letter was also addressed to US Secretary of State Anthony Blinken.
The Israeli military attack on Gaza in response to the Hamas attack on October 7 sparked increasing international criticism, as the Gaza Ministry of Health reported that more than 33,000 people had died in the war and that the narrow coastal strip was suffering from widespread famine.
Pelosi's support for halting arms transfers to Israel showed that this was a mainly prevailing position within the party.
Nancy Pelosi is a key ally of Biden and a veteran member of the Democratic Party to which the US President belongs.
In their letter, the representatives called on the Biden administration to conduct its investigation into an Israeli air strike that killed seven employees of the World Central Kitchen charity on Monday.
"Given the recent strike on aid workers and the worsening humanitarian crisis, we believe it is unjustified to approve these arms transfers," said the letter signed by Pelosi and 36 Democrats.
For its part, the Israeli army said on Friday that it had dismissed two officers and issued a formal reprimand to senior commanders after an investigation into the killing of aid workers concluded that there were serious errors and violations of procedures.
Biden made a phone call with Israeli Prime Minister Benjamin Netanyahu on Thursday, in which he said that Israel must do more to protect civilians; otherwise, the United States will change its policy.
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