Biden was speaking to about 200 people when the heckler shouted: "As a rabbi, I need you to call for a ceasefire right now."

Biden responded: "I think we need a pause. A pause means give time to get the prisoners out."

The White House later clarified that Biden was referring to the hostages - not prisoners - held by Hamas after its Oct. 7 attack on Israel in which 1,400 people were killed and more than 200 taken hostage.

Israel has vowed to annihilate Hamas and has retaliated with bombardments of Gaza and a ground offensive in the besieged coastal enclave.

The White House has previously said it supports a "humanitarian pause" to allow aid deliveries to Gaza and the release of hostages.

Biden has thrown his support behind Israel - and visited the country last month - but he has shifted his response in recent weeks as the humanitarian situation worsens in Gaza and the civilian death toll rises.

At a congressional hearing on Tuesday, two of Biden's top advisers were interrupted repeatedly by protesters denouncing American officials for backing what they called "genocide" against Palestinians in Gaza.

Biden's heckler on Wednesday, who told reporters that her name was Rabbi Jessica Rosenberg, was escorted out by security while singing "ceasefire now." Biden went on to say that he understands the emotions around the conflict in the Middle East.

"This is incredibly complicated for the Israelis. It's incredibly complicated for the Muslim world as well ... I supported a two-state solution; I have from the very beginning,” he said. "The fact of the matter is that Hamas is a terrorist organization. A flat-out terrorist organization."

The Gaza health ministry says at least 8,796 Palestinians in the narrow coastal enclave, including 3,648 children, have been killed by Israeli strikes since Oct. 7. The Hamas-run government said at least 195 Palestinians died in Israel's attacks on the Jabalia refugee camp on Wednesday.