In a video posted on Facebook, the president said that the current immigration system is "broken" and that he will address "the things that I can do with my lawful authority as president to make the system work better, even as I continue to work with Congress and encourage them to get a bipartisan comprehensive bill that can solve the entire problem."
The speech at the White House is scheduled for 8pm ET.
The Thursday evening announcement will be followed by a rally at a Las Vegas high school on Friday afternoon. Obama will be accompanied by Senate Majority Leader Harry Reid at that event, a source told NBC News.
A new NBC News/ Wall Street Journal poll shows that the country is divided about whether Obama should take executive action to address the issue of undocumented immigrants in the United States. Nearly half - 48 percent - oppose executive action, while 38 percent support it.
Republicans have slammed the president's approach, calling it an overstep of his constitutional power.
"If 'Emperor Obama' ignores the American people and announces an amnesty plan that he himself has said over and over again exceeds his Constitutional authority, he will cement his legacy of lawlessness and ruin the chances for Congressional action on this issue - and many others," said Michael Steel, a spokesman for House Speaker John Boehner.