Sen. Jeff Flake, R-Ariz., is preparing a bill that would extend the March 5 deadline for reaching a deal to protect Dreamers, or immigrants who came to the U.S. illegally as children.

President Trump set the deadline as he announced the rescission of the Obama administration’s Deferred Action for Childhood Arrivals program. While the administration has indicated it would not target DACA participants for immigration enforcement while Congress considers a way to create a new program, some lawmakers are worried that once the deadline passes, these immigrants may be more at risk of facing deportation.