WASHINGTON (AP) — Acting Homeland Security Secretary Kevin McAleenan on Sunday defended conditions at U.S. Border Patrol stations following reports of crowded and unsanitary conditions that have heightened debate about President Donald Trump's immigration policy, a trademark issue for his reelection campaign.

"It's an extraordinarily challenging situation," McAleenan told ABC's "This Week."

The Homeland Security Department's internal watchdog provided new details Tuesday about severe overcrowding in Texas' Rio Grande Valley, the busiest corridor for illegal crossings. The report said children...