An Alabama woman who joined the Islamic State group in Syria won't be allowed to return to the United States with her toddler son because she is not an American citizen, the U.S. said on Wednesday. Her lawyer is challenging that claim.

In a brief statement, Secretary of State Mike Pompeo gave no details as to how the administration made their determination.

"Ms. Hoda Muthana is not a U.S. citizen and will not be admitted into the United States," he said. "She does not have any legal basis, no valid U.S. passport, no right to a passport nor any visa to travel to the United States."