US National Security Council Coordinator for Strategic Communications John Kirby speaks during the White House daily briefing
US National Security Council Coordinator for Strategic Communications John Kirby speaks during the White House daily briefing AFP

The United States has told Israel of its concerns about civilian casualties in Gaza, the White House said Wednesday, after President Joe Biden warned Israel it could lose support over "indiscriminate bombing."

Biden's comments on Tuesday were his strongest criticism yet after resolutely standing up for Israel's right to defend itself after the October 7 attacks by Hamas.

"We have had concerns," National Security Council spokesman John Kirby said when asked about Biden's remarks to donors to his reelection campaign at an event in Washington.

"And we've expressed those concerns about the prosecution of this military campaign, even while acknowledging that it's Hamas that started this," Kirby told reporters.

Biden himself had laid out those concerns "publicly and privately" with Israeli Prime Minister Benjamin Netanyahu, Kirby said.

Israel had shown a "clear intent" to reduce civilian casualties, including carrying out fewer air strikes since it resumed its offensive after a ceasefire with Hamas broke down, Kirby added.

But he added: "Sometimes in war the best laid plans don't get executed the way you want."

Kirby also played down Biden's comments that Netanyahu had to "change" his policy opposing a two-state solution, and that the Israeli premier's hard-right government was "making it very difficult for him to move."

"We're not dictating terms," Kirby said. "It's not for us to dictate terms to a foreign sovereign government."