TEL AVIV -- Secretary of State Antony Blinken vowed on a visit Thursday that the United States will "always" back Israel but said the Palestinians also have "legitimate aspirations" not represented by militant group Hamas.

"You may be strong enough on your own to defend yourself," Blinken said during a meeting with Prime Minister Benjamin Netanyahu as war raged between Israel and Hamas. "But as long as America exists, you will never, ever have to. We will always be there by your side."

Paying a solidarity visit as Israel's army hammers Hamas over weekend attacks that killed 1,200 people in Israel, Blinken also gave a new death toll for US citizens, saying at least 25 were confirmed among the dead.

President Joe Biden has vowed unwavering support for Israel and not called for restraint against Hamas, but Blinken hinted at the need for an eventual peace settlement -- an idea that has long met resistance from the right-wing Netanyahu.

"Anyone who wants peace and justice must condemn Hamas' reign of terror. We know Hamas doesn't represent the Palestinian people, or their legitimate aspirations to live with equal measures of security, freedom, justice opportunity and dignity," Blinken said.

Speaking in unusually personal terms, Blinken recalled how his grandfather fled anti-Semitic pogroms in Russia and his stepfather survived Nazi concentration camps.

"I come before you not only as the United States secretary of state but also as a Jew," said Blinken, who has a secular background.

"I also come before you as a husband and father of young children. It's impossible for me to look at the photos of families killed, such as the mother, father and three small children murdered as they sheltered in their home in Kibbutz Nir Oz, and not think of my own children," he said.

Blinken promised that the Biden administration and Congress would work together to meet military requests for Israel, which enjoys wide support across party lines.

"As Israel's defence needs evolve, we will work with Congress to make sure that they're met," he said.

Netanyahu, speaking next to Blinken, voiced appreciation for US support and said that Hamas, which rules the blockaded Gaza Strip, should be treated like the Islamic State group.

"Just as ISIS was crushed, so too will Hamas be crushed. And Hamas should be treated exactly the way ISIS was treated," Netanyahu said. (AFP)