The Los Angeles County fairgrounds will be used to temporarily house unaccompanied children arriving at the U.S.-Mexico border, officials said Friday.

County Supervisor Hilda L. Solis said the campus in Pomona could be used to house as many as 2,500 young people once the contract is completed. She said the site will not be a detention facility and expects the county and local organizations will provide educational, mental health and legal services.

“The soul of our country is often put to the test. This is one of those moments,” Pomona Mayor Tim Sandoval told reporters. “This is the right thing to do.”

Fairplex is a 487-acre site that hosts the annual county fair and has an array of facilities for year-round business. It will be the second site in Los Angeles County to house the children after Long Beach earlier this week agreed to use its convention center.

The Biden administration has opened a series of sites to house migrant children until they are reunited with family or sponsors in the United States following an increase in arrivals on the border.

Bonnie Preston, acting regional director for the Department of Health and Human Services region covering California, said the children in Pomona would likely range from 12 to 17 years old.

“We’re looking to the county to help in this humanitarian mission in the way that California usually does it,” she said. “They step up, and they go big.”

It will be the second site in LA County to house the children. Long Beach on Tuesday agreed to lease its Convention Center to the federal government to hold up to 1,000 unaccompanied migrant children.