After months of delay, the White House on Wednesday announced that President Obama will speak to the nation at 8 pm ET to lay out his plans for immigration reform, as officials indicated his executive actions could shield upwards of 5 million people now living illegally in the United States.

"Tomorrow night, I'm going to be announcing, here from the White House, steps we can take to fix our broken immigration system," the President said in a video posted on the White House website.

"What I'm going to be laying out is the things that I can do - with my lawful authority as President - to make the system work better," Mr. Obama said while sitting on his desk in the Oval Office.

The announcement came as Republicans lobbed more verbal warning shots at the White House over immigration reform, arguing unilateral action was a political mistake.

"The latest indications that you will take executive action on immigration later this week are a slap in the face to the American people and the Constitution," said Rep. Robert Goodlatte (R-VA) and Rep. Michael McCaul (R-TX) in a letter to Mr. Obama.