(CNN) A pregnant teenager and a nine-month-old child were held in an upstate New York US Border Patrol station for around ten days while authorities tried to find them placement in a more permanent facility, according to a US Border Patrol official and a second source familiar with the situation.

This comes at a time when US officials have increasingly raised concerns about the length of time migrants are spending in Border Patrol custody, particularly as the number of migrant families and children continues to rise to unprecedented levels at the US-Mexico border.

The Border Patrol official described the station as a "really short-term" facility. It is "not meant to hold babies," they said. "Imagine, it's concrete."

Border Patrol agents apprehended the 17-year-old, who is believed to have Romanian nationality, along with her baby and three other individuals around May 21 after crossing into the US from Canada, according to the official. After she was apprehended, Border Patrol notified the US Department of Health and Human Services, which is responsible for placing and caring for unaccompanied migrant children.

The teenager was concerned about why she was being held for so long, asking, "Why?" according to the official. The official said she was told, "We are waiting for the space," and "Maybe tomorrow."

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