'We stand with Israel': Biden vows U.S. support in face of 'pure, unadulterated evil'

WASHINGTON — President Joe Biden passionately condemned Hamas’ terrorist attacks in remarks Tuesday from the White House, three days after Hamas fighters launched a surprise attack on Israel, prompting an all-out war between the two sides.

"In this moment, we must be crystal clear," Biden said. "We stand with Israel. We stand with Israel."

In his 10-minute address, Biden voiced revulsion over the "vicious attacks," which he said led to 1,000 Israeli and at least 14 American deaths.

"There are moments in this life when pure, unadulterated evil is unleashed on the world," Biden said with Vice President Kamala Harris and Secretary of State Antony Blinken standing behind him. "The people of Israel lived through one such moment this weekend."

Biden disclosed for the first time that Americans are among those taken hostage by Hamas fighters. He did not specify how many; a White House national security official said Tuesday that 20 Americans are unaccounted-for after the attacks. Biden said he has directed U.S. officials to offer their expertise in assisting Israel's efforts to free the hostages.

"As president," he said, "I have no higher priority than the safety of Americans being held hostage around the world."

Biden spoke with equal parts rage and resolve as he enumerated Hamas' atrocities in carrying out the attack.

"Infants in their mothers' arms, grandparents in wheelchairs, Holocaust survivors abducted and held hostage — hostages who Hamas has now threatened to execute in violation of every code of human morality," he said. "It's abhorrent."

Biden spoke after a phone call with Israeli Prime Minister Benjamin Netanyahu. An open question is whether Biden will let Israel conduct the war as it deems necessary or urge restraint if civilian casualties in Gaza pile up. But he did not clarify whether Israel should observe any limits in rooting out Hamas fighters; he took no questions after he finished speaking.

Biden is expected to face competing pressures within and outside the Democratic Party that could make it more difficult to keep his pledge to provide support for Israel’s plans to defend the country.

Biden also made a passing reference to the dysfunction in Washington: The House has no speaker because of infighting among the majority Republican Party. When Congress returns to work, he said, he will ask members to take "urgent actions to fund the national security requirements of our critical partners."

"This is not about party or politics," he said. "It's about the security of our world."

Biden expressed sympathy for the victims.

"You all know these traumas never go away. There's still so many families desperately waiting to hear the fate of their loved ones, not knowing if they're alive or dead or hostages," he said.

Israel’s military claimed Tuesday to have regained control inside the country after it ordered a “full siege” of Gaza, meaning no food, gas or power would be allowed into the densely populated area, Defense Minister Yoav Gallant said.

Fears have grown over the hostages Hamas fighters seized as they attacked parts of southern Israel. The militant group threatened to start executing them if Israel bombed civilian targets in Gaza.

"This attack has brought to the surface painful memories and the scars left by a millennia of antisemitism and genocide of the Jewish people," Biden said.

At a news conference Monday morning in Tel Aviv, the families of Americans believed to have been taken hostage called on Biden to take action to bring them home.

After he said the Israeli government has the responsibility of bringing back all hostages, the son of missing Adrienne Neta, 66, stressed the Biden administration also shares responsibility for every U.S. citizen whose life is at stake in the Israel-Hamas war.

“They’re responsible to bring the U.S. citizens back home, safe and sound. We expect nothing less from the U.S. administration from President Biden and Secretary of State Blinken,” he said. “I speak in the name of myself and my family, and I wish for the quick solution for this terrible, terrible situation that all of us are in.”

In support of Israel, the Biden administration is sending ships from the Navy’s USS Gerald R. Ford Carrier Strike Group to the eastern Mediterranean Sea, and officials plan to keep in place some F-16 and A-10 fighter jets that had been scheduled to rotate out of the region, a U.S. official told NBC News. The move is intended to signal a message to “stand down," an official said.

Blinken is headed to Israel on Wednesday and scheduled to arrive Thursday, the State Department announced. The trip will include Blinken’s “meeting with senior leaders in the Israeli government” and continuing “discussions he and the president have been having with them since the initial attack,” a spokesperson said.

The death toll from the war had soared to more than 1,600 people Tuesday morning, three days after Hamas fighters launched surprise attacks on Israel, officials said.

Peter Nicholas and Peter Alexander reported from Washington. Summer Concepcion reported from New York.

This article was originally published on NBCNews.com