(Reuters) - U.S. immigration officials on Thursday defended a new policy that ends automatic citizenship for some children born to U.S. citizens stationed abroad as government employees or members of the U.S. military, saying it would only affect a “handful” of families every year.

FILE PHOTO: Sailors from U.S. Navy position a power module during a biennial exercise conducted by military and civilian personnel from the United States and the Republic of Korea, as a part of the large Foal Eagle 2017 exercise off the coast of Pohang, South Korea, April 9, 2017. Courtesy Joshua Fulton/U.S. Navy/Handout via REUTERS

“It bears repeating that this affects a very small population of individuals and they have another means of obtaining citizenship for their children,” a U.S. Citizenship and Immigration Services (USCIS) official said in a call with reporters, adding that the new pathway “just requires different paperwork.”

Under current policy, children of service members and other officials stationed abroad are considered to be “residing in” the United States, so they receive the same automatic citizenship as if they were born on U.S. soil.

But under a policy USCIS announced on Wednesday, effective Oct. 29, certain parents will be required to go through a formal application process seeking U.S. citizenship on their children’s behalf by their 18th birthday.

USCIS officials said the policy may affect children born to non-citizens serving in the military, as well as children adopted by U.S. citizens stationed abroad. The policy could also affect children born to two U.S. citizens who do not meet requirements for showing a physical presence in the United States, the officials said.

A “fact sheet” posted on the USCIS website suggested the new policy would be limited in scope, saying it would exempt children born abroad to a U.S. citizen who was physically present on U.S. territory for at least five years.

“This really is a very small population,” a different USCIS official said. “Our records that we ran reflected possibly 20 to 25 people over the past five years per year.”

The announcement of the new policy swiftly drew criticism, particularly from critics of U.S. President Donald Trump, who has pushed for policies that make it harder for immigrants to come to, and settle in, the United States.

Acting USCIS director Ken Cuccinelli said on Twitter on Wednesday that the new rule “does NOT impact birthright citizenship” - the doctrine, criticized by Trump, by which anyone born in the United States or its possessions automatically acquires U.S. citizenship.

The new policy, which is not retroactive, sparked immediate consternation on the part of some organizations representing members of the armed forces.

“Military members already have enough to deal with, and the last thing that they should have to do when stationed overseas is go through hoops to ensure their children are U.S. citizens,” said Andy Blevins, executive director of the Modern Military Association of America, which advocates for gay and lesbian service members.

The USCIS officials said the agency was changing its interpretation of a statute known as the Immigration and Nationality Act in order to match State Department policies.

“[C]onsistent decision-making is important no matter the size of the affected group, so when the Department of State approached us, USCIS, about making this change, we agreed,” the official said.

The State Department did not immediately respond to a request for comment.