WASHINGTON
--

President Barack Obama plans to appoint a former senior Army official with a career in intelligence to lead the Transportation Security Administration.

The president is expected to announce his choice, retired Gen. Robert Harding, on Monday, according to an administration official who spoke on condition of anonymity because the announcement is not yet public.

The president's decision to appoint someone with an extensive intelligence background is significant because it comes after the attempted Christmas airliner attack, when the government's intelligence programs came under scrutiny and attacks by critics who said the Obama administration wasn't doing enough to foil would-be terrorists. The incident prompted a review of U.S. security policies.

The administration official said the TSA administrator is the most important unfilled post in the Obama administration.

Harding served in the Army for 33 years and retired in 2001. He has been the Defense Department's top human intelligence officer and managed a $1 billion intelligence collection program. Between 2003 and 2009, Harding was a government consultant on human intelligence and counterintelligence issues. He sold his company in 2009, according to the administration official.

Obama's original pick for the TSA job, Erroll Southers, withdrew his name from consideration in January when it became clear he would face a tough confirmation battle in the Senate.

The president has been criticized for leaving the TSA job open for so long. It took him eight months to nominate Southers.