Washington: US President George W. Bush's top defence advisers have recommended to keep 15 combat brigades in Iraq until the end of the year, the Associated Press has learnt.

The plan, which military leaders revealed to AP, would be contrary to expectations that the improved security in Iraq would allow for quicker cuts.

The military leaders said the plan would send a small Marine contingent to Afghanistan in November to replace one of two Marine units expected to head home then.

If Bush should follow the recommendations, he would delay any additional buildup in Afghanistan until early next year, when another brigade would be deployed there.

Several senior military and defence officials described the recommendations on condition of anonymity because the plan has not been made public.

They also acknowledged the plan is a compromise, since General David Petraeus, the top US commander in Iraq, argued to maintain the current force levels in Iraq through June.

That is about 146,000 troops, including 15 combat brigades and thousands of support forces.

One senior military official said it is critical to replace the Marines in Afghanistan beginning this year.

"We believe the risk in Afghanistan is such that we need to do something, and the risk in Iraq is such that we can go into Afghanistan without risking unduly the posture in Iraq," said the official.