U.S. Customs and Border Protection officials have requested airplanes to fly migrants to the U.S.-Canadian border for processing amid a surge in illegal crossings at the southern border, The Washington Post reported on Friday.

Border officials asked CBP to make the request to U.S. Immigration and Customs Enforcement (ICE) after 1,000 migrants, including unaccompanied minors, crossed the Rio Grande into South Texas on Friday morning, while another 1,000 who crossed on Thursday night were still waiting to be processed, according to an email reviewed by the Post.

The agency has not yet determined which northern states would receive the migrants.