In an interview Thursday with "World News Tonight" anchor David Muir, Secretary of State Antony Blinken expressed his disgust and anger with Hamas after he saw the gruesome details from last weekend's attack.

During a meeting with Israeli Prime Minister Benjamin Netanyahu earlier in Israel, Blinken said he was shown images and videos of the victims who were killed and wounded during last weekend's attack.

Blinken said that the images, many of which were not seen before, were "genuinely overwhelming."

"A young infant riddled with bullets, a family hugging each other, in a death embrace, having been burned to death, beheaded soldiers," Blinken said, describing what he saw. "It almost defies human comprehension precisely because it's not human."

-ABC News' Ivan Pereira

New York City Mayor Eric Adams said there are "no credible or specific threats" against the city ahead of Friday, when Hamas is calling on their supporters to hold worldwide "Day of Rage" protests that could turn violent.

"We are deeply disturbed by the message of hate. It is not acceptable," Adams said during a briefing.

The mayor said he has directed the NYPD to surge additional resources to schools and houses of worship "to ensure that they are safe." Police are also stepping up patrols in certain neighborhoods, he said.

New York Gov. Kathy Hochul also said at the briefing there is no intelligence "showing any active threats" in the state but "we will continue to exercise elevated vigilance."

She said state police have been "fully activated" and the National Guard has been directed to patrol key transportation hubs.

"There's no reason to feel afraid," Hochul said.

In an interview with ABC News Live, Michael Oren, the former Israeli ambassador to the U.S., warned that we are just at the "beginning of this war."

Oren said the possibility of another front is "almost certain now," saying he thinks Hezbollah will join the conflict. He also warned that this war will differ from past ones in the region like the Six Day War and Yom Kippur War because this will be fought in locations that are densely populated with civilians.

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Former Israeli ambassador discusses impact of US support

Michael Oren, the former Israeli ambassador to the U.S., details what American support means for the increasing conflict.

"This war, by very marked contrast, is fought in the Israeli heartland," Oren said. "It is the vast majority of our casualties are civilians. We're fighting against an enemy that wants to destroy us at any cost and will do so in the most brutal manner and massacre our civilians."

Oren said the support from the U.S. has been crucial during a time of great "agony."

"To have the leaders of the most powerful country in the world, to come out in support of us in that way, so categorically, so unequivocally condemning terror was very moving for all of us, a great source of relief," Oren said.

When asked about the possibility of another front opening in the war, Iranian Foreign Minister Hossein Amir-Abdollahian told reporters that "anything is possible."

"Our clear-cut response about future possibilities is that everything is dependent on the moves of the Zionist regime in Gaza," Amir-Abdollahian said at the airport in Beirut.

Following Israel's siege of Gaza, including cutting off its water supply and power, and the death of Palestinian civilians, "anything is possible, and we may witness new events in the region," he said.

Iran, which does not recognize Israel, has acknowledged giving financial and moral support to Hamas.