It remains unclear exactly what Gen Lute's remit might be

Lt Gen Douglas Lute, currently serving as director of operations at the Pentagon, will co-ordinate the ongoing conflicts in Iraq and Afghanistan.

He will report directly to Mr Bush as deputy national security adviser.

Gen Lute was appointed after a lengthy search in which several candidates apparently turned down the position. He must be confirmed by the US Senate.

President Bush is expected to make an official announcement about Mr Lute's appointment on Wednesday.

Turf wars

If confirmed, Gen Lute, 55, would take his post as the US battles militants in Iraq and Taleban rebels in Afghanistan.

LT GEN DOUGLAS LUTE Graduated from West Point academy 1975 Active in 1991 Gulf War Commander, Kosovo, 2002 US Central Command, 2004-06 Pentagon 2006-07

Correspondents say it is unclear exactly what General Lute will do, and whether the job will involve settling turf wars between the Pentagon and the state department.

He will serve as an adviser to the president but will also keep his military position and three-star ranking, reports said.

The Associated Press news agency reported that the new appointee would speak for the president concerning developments in the conflict areas and smooth over differences between rival departments.

Several White House security officials have left the administration in recent months.