Washington-area officials are bracing for the arrival — and potentially extended stay — of children who crossed the United States-Mexico border from Central America and are seeking asylum. And some are demanding to know just how many children are already here.

Although specific numbers are unavailable about the number of children who have been brought to the area as the crisis along the border has escalated in recent months, local groups say the surge is noticeable. Federal immigration authorities say there are 5,723 cases pending in local immigration courts that involve juveniles from Central American countries facing deportation.

The Obama administration says it is pushing to send those children home as quickly as possible but has allowed many of them to temporarily reunite with parents or legal guardians in the United States, while others without local family ties are being housed at military facilities and centers operated by nonprofit groups.

That has led to an influx of migrant children to the Washington area, where immigrants from Guatemala, El Salvador and Honduras are the second-largest Central American community in the country.

Roxana Olivas, director of Latino affairs in D.C. Mayor Vincent C. Gray’s administration, said a city school program geared toward Central American children has lately had 30 new students a month.

Corey Stewart (Dayna Smith/The Washington Post)

“We’ve been going at this for a while,” Olivas said. “We just don’t know the extent of it yet.”

With many of those children seeking asylum — which could take months if not years to be resolved — officials in the suburbs are wondering how their communities will be affected and whether additional services will be needed.

“I know we’re going to have an avalanche,” said Montgomery County Council member Nancy Navarro, who is pushing officials to explore how the Maryland suburb’s schools and social services will be affected by a continuing influx of cases to the region.

“It’s just inevitable,” added Navarro (D-Mid-County.)

Jennifer Harris, director of communications for Arlington public schools, said in an e-mail that the school system doesn’t “have an accurate picture yet” of the likely impact. She added that public schools “are required by federal law to . . . provide an education to students who request an education, regardless of their immigration status.”

In some instances, the influx has angered some residents and led to the type of complaints that have fueled protests in other parts of the country, where activists have demanded that the children be returned home immediately.

“At the end of the day, there is a good possibility that these children are going to need county services — education, medical and social services — and the county is going to have to end up being the caretaker of these children,” said Corey A. Stewart, the chairman of the Board of Supervisors in Prince William County.

That Northern Virginia community has seen a backlash to news that a local nonprofit organization has begun caring for some of the children inside one of its centers.

In Fairfax County, Supervisor Penny Gross compared what’s happening at the border to the crisis after Hurricane Katrina in 2005, where there was a sudden need nationwide to assist several thousand families.

“This is a serious, serious issue,” said Gross (D-Mason). “We don’t know what to expect.”

Arlington County said it is preparing to train its social-services staff to deal with issues involving the migrant children.

“Bottom line: No easy answers,” said county spokesman Kurt Larrick. “But we have a strong child-welfare system in Arlington . . . and we are committed to the health and safety of any child in our community.”

Federal officials said the impact on local municipalities will be minimal.

The U.S. Department of Health and Human Services, whose job is to ensure that the children are cared for while they await deportation proceedings, said it helps fund the cost of food, clothing, school and medical screenings when the children are housed at a shelter.

“Children spend less than 35 days on average at the shelters and do not integrate into the local community,” Kenneth Wolfe, an agency spokesman, said in an e-mailed statement.

But during a Juvenile Court proceeding at a federal immigration court in Arlington on Wednesday, some children left with the impression that they’d be around for a while.

John Bryant, an immigration judge, went through his busy caseload, engaging in idle chitchat with each of about a dozen teenagers who appeared before him to put them at ease.

He then ordered them to come back in several months, with one child seeking asylum told to return in February 2017.

Bill Turque contributed to this report.