(WASHINGTON) — The U.S. remains committed to “ongoing negotiations” for the release of hostages believed to be held by Hamas in Gaza as officials work to find nine Americans still missing in the wake of the extremist group’s Oct. 7 terror attack on Israel, the White House’s national security adviser said on Sunday.

“There are ongoing negotiations involving the Israelis, the Qataris, and we, the United States, are actively engaged in this as well because we want to make sure that we bring home those Americans who have been taken hostage as well as all of the other hostages,” Jake Sullivan told ABC “This Week” co-anchor Jonathan Karl.

Pressed by Karl on the total number of hostages, Sullivan said America doesn’t have a “precise number.”

“We know the number of missing and that’s the number the Israelis have given. But we don’t know how many of those are still alive,” Sullivan said. “As far as the Americans are concerned, there are nine missing American citizens as well as a missing legal permanent [resident], a green card holder.”

Sullivan continued: “That’s the number that we are trying to ensure the safe return of, and we have been engaging with the families. In fact, I will personally be seeing family members of the American hostages this coming week.”

Karl also asked Sullivan if the U.S. believes Hamas’ claim that a number of hostages were killed in Israeli retaliatory strikes in Gaza.

“Well, first, we don’t take anything Hamas says at face value, but we have no information that can either corroborate or counteract that,” Sullivan replied. “So as I said before, we simply don’t know how many of the hostages are still alive, how many have been mistreated, how many Hamas itself has killed just as it slaughtered hundreds and hundreds of people when it conducted those gruesome and horrific terrorist attacks on Oct. 7.”

According to the Associated Press, Israeli officials said Saturday that “around 1,200” were killed by Hamas militants in the terrorist attack just over a month ago. That total was revised from an earlier figure of about 1,400.

In a separate appearance on “This Week,” Reps. Mike Lawler, R-N.Y., and Jared Moskowitz, D-Fla., spoke about their recent trip to Israel, where they met with Prime Minister Benjamin Netanyahu prior to the interview.

“We engaged in a very thoughtful conversation about the need for Congress to pass aid to Israel and our support and our commitment to our closest ally in the region,” Lawler said.

Moskowitz also touched on the efforts to find the captives in Gaza. “There are not a lot of good options. The hostages are in a number of places, some are in the tunnels, some are not in the tunnels,” he said, later adding, “They’re working on several plans to locate the hostages. I don’t want to go into details of that, but obviously, that is a top priority.”

Sullivan, in his interview, was asked if medical facilities in Gaza, like the Al-Shifa hospital now at the center of some of the fighting, have become legitimate military targets considering Israel says Hamas has built tunnels underneath them in order to operate.

Sullivan said the U.S. does not want to see a “firefight” break out at any hospital but he stressed that there are many publicly available indications that Hamas uses civilian areas “to store weapons, for command and control, to house its fighters.”

He called that “a violation of the laws of war.”

Nonetheless, Sullivan said the United States doesn’t want a situation “where innocent people, helpless people, people seeking medical care are caught in the crossfire.”

“This just points [to] how difficult this military operation is, because Israel has an added burden given the way that Hamas operates — but it does not lessen their responsibility to protect civilians,” he added.

Israeli military officials have maintained that they do not target hospitals and have said they’re taking steps to help patients leave Al-Shifa.

More than 11,000 people have been killed in Gaza, according to the Hamas-run Gaza Health Ministry. On Friday, Secretary of State Antony Blinken said the death toll was already too high

“Far too many Palestinians have been killed, far too many have suffered these past weeks, and we want to do everything possible to prevent harm to them and to maximize the assistance that gets to them,” Blinken said after a multi-day trip to the region. “To that end, we’ll be continuing to discuss with Israel concrete steps that can be taken to advance these objectives.”

Sullivan on Sunday was pressed by Karl on whether Israel was doing enough to prevent civilian casualties, referencing Blinken’s comments. Sullivan reiterated that concerns for civilians have been impressed upon the Israelis by President Joe Biden, Blinken and himself.

“The loss of a single innocent life is a tragedy, whether it’s Palestinian or Israeli or anyone and we grieve for every lost innocent,” Sullivan told Karl. “We believe in the sanctity of life.”

“And so they are taking measures to try to go after the terrorists. It’s their obligation to do so in a way that separates the terrorists from innocent Palestinian civilians,” Sullivan said.

Moskowitz and Lawler, in their own interview, said that Israel had a right to defend itself against Hamas. While Lawler said humanitarian relief should be provided, he supported Israel’s expansive military operations in Gaza against Hamas.

“For those calling for a cease-fire, they totally misunderstand the situation here,” he said. “Hamas is not someone, some organization that is going to abide by a cease-fire. They are hell-bent on eradicating the state of Israel.”

Looking to the future, however, Sullivan said the conflict should not end with an Israeli reoccupation of Gaza.

“We will work with all of our partners, with the Israelis, with countries in the Arab world and especially with the Palestinians, so that they can have a voice in what the future governance of both the West Bank and Gaza look like,” he said.

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