Men, women and children walk on the US side of the US-Mexico border after crossing the Rio Grande river that divides the two countries, before surrendering and being processed by US Customs and Border Protection agents. The US is readying its response to an expected surge of migrants seeking to enter as tens of thousands of people are waiting at crossing points for the end of pandemic-era rules that had forbidden virtually all asylum claims at the border. The so-called Title 42 expires overnight Thursday into Friday.