PRESIDENT DONALD TRUMP is expected to sign an executive order on immigration that will be a radical departure from decades of U.S. policy on refugees, all but ending an era in which the United States was a haven for people fleeing war and oppression.

A leaked copy of the draft order indicates that Trump will halt all refugee resettlement to the United States for the next four months, while indefinitely banning the resettlement of Syrians. The proposal will also halt immigration entirely for 30 days from a list of Muslim-majority countries.

The order comes at a time of rising anti-Muslim sentiment in the United States, as well as an international refugee crisis that the United Nations says is the largest since World War II. Millions of refugees are fleeing countries like Iraq and Syria — where the United States has ongoing military operations. While the U.S. has resettled tens of thousands of people from these countries over the past decade, that slightly-ajar door now appears to be slamming shut.

Trump has argued that new restrictions on refugees and immigrants are required to combat the threat of terrorism in the United States. But his proposal is a drastic change for U.S. policy. Since 1975 the United States has accepted over 3 million refugees, including many from war-torn countries, thanks in large part to legislation like the 1980 Refugee Act. Even under Republican administrations like that of Ronald Reagan, the United States maintained relatively generous immigration and refugee policies. During Reagan’s presidency, the United States welcomed hundreds of thousands of southeast Asian refugees fleeing war and oppression.

“Our nation is a nation of immigrants,” Reagan said in a 1981 speech. “More than any other country, our strength comes from our own immigrant heritage and our capacity to welcome those from other lands. No free and prosperous nation can by itself accommodate all those who seek a better life or flee persecution. We must share this responsibility with other countries.”

In what appears to be a recognition of the drastic changes at hand, the National Association of Evangelicals issued a statement today calling on Trump to continue accepting refugees fleeing wars in the Middle East. “News reports that the Trump administration plans to make severe cuts to the admission of refugees based on their religion or national origin are alarming,” the NAE said. “We call on President Trump to declare his support for the continuation of the U.S. refugee resettlement program, which is critical at a time when the world faces a significant refugee crisis.”

There is little indication that Trump plans to heed these calls. In addition to his public reiteration today of a promise to build a southern border wall and ramp up deportations, there have been a number of reports in the past several days of individuals from Muslim-majority countries, including students, having their visas abruptly cancelled while abroad.

“Under Trump’s direction, the Department of Homeland Security and State Department will likely work together to create a list of countries from which visitors should be banned,” says Matthew La Corte an immigration policy analyst at Niskanen Center, a public policy think tank. “We also expect this list to grow over time and be larger than the initial list of countries that has been reported in the media.”

The text of the executive order indicates that visas would be blocked for individuals visiting the United States from Syria, Iraq, Iran, Libya, Somalia, Sudan and Yemen, all countries with Muslim-majority populations. Trump made a campaign promise to ban Muslims from entering the United States, and the draft text of the executive order calls for the U.S. to ban “those who would place violent religious edicts over American law.”

Farhana Khera, executive director of Muslim Advocates, a legal advocacy organization, said that the proposed executive order would, “elevate the most bigoted stereotypes of Muslims and Islam perpetuated by anti-Muslim hate groups to the level of U.S. government policy.”

Khera added, “Based on what we’ve seen, we are deeply concerned that this order will erode our fundamental values as a country. The United States was founded as a haven for people fleeing persecution. Trump’s proposal undermines that principle while making good on his outrageous promise to ban Muslims from entering the U.S. entirely.”

While full details of the order are not yet clear, its impact on refugees fleeing wars in the Middle East will be immediate and devastating. Last year President Obama reached his target of resettling 10,000 Syrian refugees, and more were expected to arrive in the coming year. This process is now expected to come to a complete halt, even for Syrians who have already been vetted and cleared for arrival.

“This is going to be devastating for refugees around the world. Pulling the U.S. out of its traditional leadership role in resettlement makes it harder to justify refugee resettlement as a good policy for other countries as well,” said La Corte. He added that banning refugees on national security grounds is a misguided policy, as refugees are already the heavily vetted and are themselves fleeing violence.

“At the end of the day refugees are not the perpetrators of violence, they’re the victims of it,” he said. “They’re the ones fleeing oppressive governments and terrorist groups, and they now face violence at home and bans on their presence abroad. What Trump is doing is not just un-American, its inhumane.”

Top photo: A woman cries as she and others wait for hours inside a police cordon, hoping to cross the border into Macedonia on March 6, 2016.