On Thursday, Mr Netanyahu met Mr Biden and Ms Harris, now the presumptive Democratic nominee for President.
Afterwards she said she had raised the issue of the civilian deaths and vowed she would “not be silent” about the topic.
Before the meeting in Florida, Mr Trump told CNN: “I think her remarks were disrespectful. They weren’t very nice pertaining to Israel.”
He added: “I actually don’t know how a person who is Jewish could vote for her, but that’s up to them.”
Critics of Ms Harris claimed her comments could make it harder for Israel and Hamas to broker a ceasefire, something her team has rejected.
“I think to the extent that Hamas understands there’s no daylight between Israel and the United States, that expedites the deal,” Mr Netanyahu told to reporters at his meeting with Mr Trump. “And I would hope that those comments don’t change that.”