President Donald Trump signed a new executive order Wednesday night banning people from a dozen countries from entering the United States. Haiti is one of the countries on the list.

Brockton resident Teddy Mombrun immigrated from Haiti in 2020. The former physician said he has family who would want to come to the United States, but he believes they won’t be able to after the travel ban.

“It’s very horrible because I have friends, I have people, I have family who used to try to come with their visa. Since that, they would no longer be able to come,” he said. “Given the gang violence and economic strain in the country, it’s difficult for people to stay in the country.”

The ban goes into effect Monday morning at midnight. It stems from a January executive order Trump signed that required government agencies to compile a report on “hostile attitudes” toward the United States and whether entry from certain countries represented a national security risk.

“This is gut-wrenching and it’s unfortunate,” said Marvin Mathelier, executive director of the Toussaint L’Ouverture Cultural Center in Boston, who moved to America with his family as a child.

“The message that we are seeing is that the U.S. does not stand with Haiti,” he said. “We’re isolating them and we’re just watching that country continue to be in a situation that it is in today — and it’s unfair.”

“Unfair” was the refrain from many advocates and Haitian immigrants. With the Boston area home to the third-largest Haitian community in the country, they’re expecting to see a major impact on the thousands of people who are already in Massachusetts, too.

“We’re seeing what we all know — and it’s President Trump’s xenophobic and hateful agenda that targets people in a discriminatory fashion,” said Boston City Council President Ruthzee Louijeune, a daughter of Haitian immigrants who became the city’s first Haitian American city councilor. “Like we saw last time with his [Trump’s] travel bans, the legal challenges are starting already. And it’s just going to see more challenges and more confusion and just remind people of exactly who the president is.”

Louijeune said her office is already fielding phone calls from constituents who are confused and concerned.

“They didn’t know if they could travel to their country of origin and make it back safely because of the travel bans. And it’s going to be a lot of chaos and confusion,” she told GBH News.

Organizations that help Haitians in varying legal statuses, like humanitarian parole and Temporary Protected Status, say the impact will be significant. At the International Institute of New England, more than 90% of its current clients come from nations included in the travel ban, particularly Haiti, Afghanistan and the Democratic Republic of the Congo. They have gone through rigorous vetting and screening — and trauma.

“The Travel Ban is a devastating and cruel decision that betrays our nation’s legacy of providing humanitarian assistance to vulnerable people in need around the world,” said Jeff Thielman, CEO of the organization. “The President claims he has selected these nations because they have a ‘large-scale presence of terrorists.’ In reality, the individuals seeking to leave these nations are doing so to save their lives and their families.”

Thielman said the ban also means separating families, who have spent years apart and are “desperate to be reunited.” The International Institute of New England hopes the ban is successfully challenged in court.

“These are very scary times,” Louijeune said. “It’s even more incumbent upon us to show up, to protest, to rally and to make sure that we’re standing in solidarity with the most vulnerable among us. We know that fear is going to take root, and we know that it has taken root. But we are doing everything we can at the local level to protect who we are, our values and all of our residents.”

For Mathelier, community matters now more than ever. “It has to be all hands on deck,” he said. “We need to go ahead and ensure the Haitian community is empowering and informing their elected officials — whether it is at the city, state or federal level — that the policies being imposed on Haiti are not the right way to go.”

Mathelier is also calling on the strong network of Haitian nonprofits across the region to get involved and take a stand.

“[They] could put their heads together on trying to figure out ways to support the Haitian community within the diaspora and back home. How do we go ahead and do that in the most optimal and efficient way? I think that’s the question that needs to be addressed right now.”