Previously, the partners of diplomats were granted a diplomatic visa, allowing them to enter the country. But now the White House will deny these visa requests, claiming that the change is “to help ensure and promote equal treatment.”

Starting October 1, these couples must provide proof of marriage by the end of the year or leave the country within 30 days. Any partners that are planning to come to the U.S. must similarly provide proof of marriage in order to be eligible for the diplomatic visa that allows them to enter the country. Foreign Policy, which first reported the story, estimates that as of this week at least 10 UN employees in the U.S. will be affected by the new policy.

In a letter sent to UN delegates in July, the U.S. mission to the UN explained that “same-sex spouses of U.S. diplomats now enjoy the same rights and benefits as opposite-sex spouses. Consistent with [State] Department policy, partners accompanying members of permanent missions or seeking to join the same must generally be married in order to be eligible” for the visa.

But critics of the policy say that it unfairly targets couples who come from countries where same-sex marriage is unrecognized or illegal. Only 12% or 25 of 193 UN member countries permit same-sex marriage; in more than 70, same-sex relationships are punishable by law.

Unmarried partners living in countries that do not permit same-sex marriage will potentially be forced to “choose between a posting at UN headquarters or family separation,” wrote Deputy UN Director at Human Rights Watch Askhaya Kumar. “The U.S. government should recognize, as it had for almost nine years until today, that requiring a marriage as proof of bona fide partnership is a bad and cruel policy, one that replicates the terrible discrimination many LGBT people face in their own countries, and should be immediately reversed.”