WASHINGTON - Republican lawmaker Joe Wilson, who won instant notoriety for shouting "you lie!" at US President Barack Obama, said Thursday the outburst was spontaneous and he apologized at the request of party leaders.

"Last night I heard from the leadership that they wanted me to contact the White House and state that my statements were inappropriate. I did," the South Carolina Representative told reporters clustered outside his office door.

"I'm very grateful that the White House, in talking with them, they indicated that they appreciated the call and that we needed to have a civil discussion about the health care issues," he said.

"And I certainly agree with that," said Wilson, whose shouted outburst during Obama's late Wednesday speech to a joint session of Congress drew swift condemnation from colleagues and political observers.

The Republican lawmaker, whose likely Democratic rival in the 2010 midterm elections has reportedly raised over 250,000 dollars since the outburst, expressed no remorse for his attack on Obama.

Wilson recalled that he had erupted when Obama denied his favored plan for overhauling US health care would extend to undocumented immigrants, noting that Democrats had defeated amendments aiming to explicitly exclude them.

"This is wrong. We need to be discussing issues specifically to help the American people, and that would not include illegal aliens," the lawmaker told reporters Thursday.

Asked whether his shouted charge was premeditated, Wilson replied: "I will tell you this, that it was spontaneous."