AFP - A US lawmaker who shouted "you lie!" at President Barack Obama during a speech to a rare joint session of the US Congress apologized for his outburst late Wednesday.

"This evening I let my emotions get the best of me when listening to the president’s remarks regarding the coverage of illegal immigrants in the health care bill," Republican Representative Joe Wilson said in a statement.

"While I disagree with the president’s statement, my comments were inappropriate and regrettable. I extend sincere apologies to the president for this lack of civility," the South Carolina lawmaker said.

Wilson had yelled out the accusation, rare in the formal setting of a presidential speech to a joint session of the US Congress, after Obama denied his plan would insure undocumented immigrants.

Fellow Republicans stiffened at Wilson's outburst, Democratic House Speaker Nancy Pelosi's eyes shot daggers at him, and a handful of Democrats called out their disapproval as Obama briefly paused but continued his speech.