U.S. Department of Homeland Security officials have ordered what amounts to a pause for a range of programs that allowed immigrants to settle in the United States temporarily, including a key initiative providing an entryway for Ukrainians.

The directive, contained in an email sent by the top official at U.S. Citizenship and Immigration Services on Thursday and obtained by The New York Times, demands an immediate end to "final decisions” on applications related to the programs while the administration reviews them and decides whether to terminate them.

The scope of the programs mentioned in the pause is vast, and the decision will block the entrance of immigrants fleeing some of the most unstable and desperate places in the world. In addition to Ukraine, which has been battered by years of war, the programs offered a pathway to immigrants from Cuba, Haiti and Venezuela, among others.