(WASHINGTON) — Freeing the American, Israeli and other hostages in Gaza is still a priority as Israel expands its ground assault in the territory in an effort to defeat Hamas in the wake of the group’s terror attack on Israel, the White House’s national security adviser said Sunday.

“We are continuing to see if there are ways to make that happen. We are prepared to support humanitarian pauses so that hostages can get out safely. And we will keep working at that every day because the president has no higher priority than the safe return of American citizens and wants to support the return of citizens of other countries and Israelis as well,” Jake Sullivan told ABC “This Week” co-anchor Martha Raddatz.

“Now, how exactly that happens … I cannot predict that. All I can tell you is every effort is being undertaken right now to do that,” Sullivan said.

But he noted “there are ongoing efforts which I can’t get into detail on television, including regional partners, including the Israelis.”

Hamas is believed to be holding 230 captives, an Israeli military spokesman separately told reporters on Sunday. The group has so far released four of its hostages.

Sullivan’s comments on “This Week” come as Israel has begun sending ground forces, including tanks, into the neighboring Gaza Strip, which is controlled by Hamas, compounding the retaliatory operations against the militants.

More than 8,000 people have been killed and another 21,400 injured in Gaza — with 70% of the casualties being children, women or older people — according to the Hamas-run Gaza Health Ministry.

More than 1,400 people were killed by the Hamas attacks in Israel on Oct. 7, Israeli officials have said.

Sullivan on Sunday reiterated that the Biden administration supports Israel’s right to self-defense against Hamas — though that should be balanced with Israel’s obligations to protect civilians while providing humanitarian aid in Gaza, which has largely been under blockade for more than 15 years, after Hamas took control there.

“The United States continues to stand behind a set of very core principles. Israel has a right and indeed a duty to defend itself against terrorists. Israel also has a responsibility to distinguish between terrorists and ordinary civilians. And the United States has a responsibility to do everything we can to make sure that lifesaving humanitarian assistance gets to those people who have been affected by this conflict. And we’re working at that every day,” Sullivan said.

At the same time, he said, “Israel was attacked in a brutal, vicious terrorist attack. They are taking steps to go after the terrorists who struck them.”

“Hamas, this brutal terrorist organization that conducted the attack, is hiding behind the civilian population [in Gaza], which puts an added burden on Israel to differentiate between the terrorists and innocent civilians, but it doesn’t lessen their responsibility under international humanitarian law and the laws of war to do all in their power to protect the civilian population,” Sullivan said.

“We’ll continue to ask hard questions about how they are thinking this through, how they [the Israelis] are proceeding. But, ultimately, these are their decisions,” he added.

Pressed by Raddatz, Sullivan insisted that U.S. weapons transfers to Israel come with conditions including taking steps to curb civilian casualties, as Israel has long maintained it does.

Sullivan said that those killed in Gaza “did not deserve to die” and that “Hamas is doing everything in its power to put those people in harm’s way to use them as human shields to hide rocket infrastructure and other forms of terrorist infrastructure among civilian areas.”

“Every innocent human life is sacred,” he said. “And every step must be taken to protect human life. Whether that be Palestinian or Israeli or anyone else. And there have been deaths of thousands of Palestinian civilians in this conflict, and that is an absolute tragedy.”

Raddatz also asked if Sullivan believes Israel is losing “the information battle internationally,” with global sympathies tipping toward the widespread death in Gaza rather than on the victims of the Hamas attack on Oct. 7.

Sullivan did not answer directly but said “it is understandable that people in neighboring countries and people in the farthest corners of the world, they’re looking at this as a deep, heartbreaking tragedy, because it is a deep, heartbreaking tragedy.”

Raddatz separately asked Sullivan about concerns of a growing conflict in the Middle East after the Pentagon last week struck facilities associated with Iranian-backed militant groups that had been attacking U.S. forces in Iraq and Syria.

While U.S. officials have sought to make clear that the retaliation against Iran’s proxies is different from Israel’s response to Hamas, Sullivan said there was a chance for a widening war.

“I think the Iranians understand our message, and we, of course, are taking every measure necessary to protect our forces, to increase our vigilance, and to work with other countries in the region to try to keep this conflict that is currently in Israel and Gaza from spinning out. … But the risk is real,” Sullivan said, “and, therefore, vigilance is high.”

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