WASHINGTON (AP):

White House environmental adviser Van Jones, embroiled in a controversy over past inflammatory statements, resigned after what he called a "vicious smear campaign against me".

The resignation, announced early yesterday, came as President Barack Obama is working to regain his footing in the contentious health-care debate.

Jones, who specialised in environmentally friendly 'green jobs' with the White House Council on Environmental Quality, was linked to efforts suggesting a government role in the September 11, 2001 attacks and to derogatory comments about Republicans.

Liability

Obama did not endorse Jones' comments, White House spokes-man Robert Gibbs said.

"What Van Jones decided was that the agenda of this president was bigger than any one individual," said Gibbs. Jones "understood he was going to get in the way" and becoming a liability to the administration, the spokesman said on ABC's This Week.

Jones issued an apology on Thursday for his past statements.

The matter surfaced after news reports of a derogatory comment Jones made in the past about Republicans, and separately, of Jones's name appearing on a petition connected to the events surrounding the 2001 attacks. That 2004 petition had asked for congressional hearings and other investigations into whether high-level government officials had allowed the attacks to occur.

Historic fights

"On the eve of historic fights for health care and clean energy, opponents of reform have mounted a vicious smear campaign against me," Jones said in his resignation statement. "They are using lies and distortions to distract and divide."

Jones said he has been "inundated with calls from across the political spectrum urging me to stay and fight".

However, he said he could not in good conscience ask his colleagues to spend time and energy defending or explaining his past.