US border communities declare disasters as Title 42's expiration sets the stage for a migration rush

With tens of thousands of migrants massed in northern Mexico, the expiration overnight of the US Covid-era border restriction policy known as Title 42 has American border communities on edge, worried an already challenging humanitarian crisis will worsen as crossings climb.

"We're boarding up like there were a hurricane coming," Victor Treviño, the mayor of Laredo, Texas, told CNN Thursday evening.

Live updates: The latest from the border after Title 42's expiration

The South Texas counties of Cameron and Hidalgo issued disaster declarations ahead of the order's expiration at 11:59 p.m. ET Thursday to help free up state and federal resources as US troops, agents and other federal workers surged this week toward the southern border to help handle a possible crush.

Still, officials hit a roadblock late Thursday as a federal judge temporarily blocked the Biden administration from releasing screened and vetted migrants from Border Patrol without court notices - a method it had planned to use to alleviate immense strain on border facilities. The ruling sidelines a tactic used by prior administrations and is "very harmful" in light of potential overcrowding, US Homeland Security Secretary Alejandro Mayorkas told CNN on Friday.

Meantime, new rules will limit asylum claims by migrants who traverse other countries en route to the US-Mexico border and closely track migrant families released into the US during the deportation process. The asylum rule, though, quickly drew a lawsuit from the American Civil Liberties Union and others who said it echoes Trump-era policy, breaks with US and international law and puts vulnerable migrants in harm's way.

Here are the latest developments during the first chaotic hours of the new US immigration enforcement policy: