President Bush tonight will call for deployment of National Guard troops to help seal America's border with Mexico.
Aides say the president wants thousands of guard troops to back up the Border Patrol. It would be a stop-gap measure while more border agents are hired and trained.
But lawmakers are concerned the plan would place a big, new burden on a National Guard already stretched thin by the war in Iraq. And Mexican President Vicente Fox opposes the deployment, saying it could "militarize" the border.
Bush's proposal aims to win conservative backing for a comprehensive immigration package that includes his guest worker plan.
He will speak from the Oval Office at eight pm Eastern time.