President Biden on Friday said the terrorist group Hamas, which brutally attacked Israel last weekend, is worse than al Qaeda, the organization behind the Sept. 11, 2001, terror attacks.

“The more we learned about the attack, the more horrifying it becomes. More than 1,000 — 1,000 innocent lives lost, including at least 27 Americans. These guys make, they make al Qaeda look pure. They’re pure evil,” Biden said during remarks in Philadelphia on Friday.

“The United States, make no mistake about it, stands with Israel,” he added.

Also on Friday, Defense Secretary Lloyd Austin, who is in Tel Aviv, compared Hamas to the terrorist group ISIS.

“The deliberate cruelty of Hamas vividly reminds me of ISIS: bloodthirsty, fanatical and hateful,” Austin said at a press conference with Israeli Defense Minister Yoav Gallant. “And like ISIS, Hamas has nothing to offer but zealotry and bigotry and death.”

Biden, in Philadelphia, said his administration is making sure Israel has what it needs to defend itself and respond to the Hamas attacks.

He also called the situation in Gaza a humanitarian crisis after Israel called for 1 million people in Gaza to evacuate, suggesting a ground assault could be on the way.

Biden said his team is communicating directly with the governments of Israel, Egypt and Jordan, as well as the United Nations, to surge support for the humanitarian consequences after the attack against Israel.

“We can’t lose sight of that fact that the overwhelming majority of the Palestinians had nothing to do with Hamas and Hamas’s appalling attacks, and they’re suffering as a result as well,” he said.

The president earlier on Friday spoke with the family members of Americans missing after the attacks. Fourteen U.S. citizens are unaccounted for, and the White House has said that a very small number of that group are being held as hostages.

“They’re going through agony not knowing what the status of their sons, daughters, husbands, wives, husbands, children are. You know, it’s gut-wrenching,” he said of the families of the 14 Americans.

“We’re not going to stop until we bring them home,” Biden added.

The White House has said they are focused on bringing the hostages home but have been limited on details like their whereabouts and condition.