(NewsNation) — The conflict between Israel and Hamas could spread to cities worldwide as a former Hamas chief called for a “Day of Jihad” by Muslim communities.

Khaled Meshaal designated Friday, Oct. 13, as the “Day of Jihad,” asking Muslims to take to the streets and deliver a message of anger in support of Palestinians.

U.S. Rep. Matt Gaetz, R-Fla., is among those who have responded, saying Americans will be armed and will not be intimidated.

NewsNation has also learned New York City police on duty tomorrow have all been ordered to show up in uniform and be ready to deploy. This comes as Columbia University closed its campus to the public in preparation for protests there.

Michael Balboni, former New York state homeland security adviser, joined “Elizabeth Vargas Reports” to discuss the potential threat, saying, “The thing people are most concerned about is the call for bloodshed.”

“They are not calling for peaceful protests,” he said.

Balboni stressed that there have been calls for a “Day of Jihad” before, but he said this is a different set of circumstances.

“It is an incredibly emotional time,” he said. “And so what you’re going to see is that people are very, very skittish about this. And they’re nervous.”

Balboni also stressed the importance of maintaining calm.

“New York City has been the place of protests for decades,” he said. “And the New York City Police Department is probably one of the most experienced police forces in the world.”

Furthermore, Balboni said, “If you study, in the past, types of terrorist attacks, what you realize is that it just doesn’t happen overnight.”

Balboni said typically these calls for violence don’t resonate and “doesn’t result in a concerted attack anywhere in the world itself.”

“That takes planning, that takes preparation,” he said. “And you don’t really have that.”

However, Balboni said “there’s no way” that any police force around the world is going to step back and not pay attention to a threat.

But Balboni said there are infrastructure protection strategies currently in place right now.

“They’re going to try to make sure that they have the ability, the incredible show of force, and then use the assets that they have: undercover police officers, informants. And of course, what you have in major cities, especially in New York City, is surveillance, which has been dramatically increased over the years.”

Nonetheless, Balboni said people need to pay attention.

“Be aware and take certain steps,” he said, “Know who’s coming into your building and do other things to make sure that you can limit the ability of people to perpetrate an attack.”