Washington  - The new commander of US and NATO forces in Afghanistan believes the size of the Afghan security forces would have to be greatly expanded to achieve success in the Central Asian country, a newspaper reported Saturday.

General Stanley McChrystal is working on an assessment of the Afghanistan mission, which is due next month, but he has been lobbying before its completion for substantially beefing up the Afghan forces, The Washington Post reported, citing unnamed senior military officials in Washington and Kabul.

An expansion of the Afghan army from 85,000 troops to 134,000 by 2011 is already planned, but US Defense Department officials told the Post that an adequate force might consist of twice that number of soldiers.

"There are not enough Afghan National Army and Afghan National Police for our forces to partner with in operations ... and that gap will exist into the coming years even with the planned growth already budgeted for," a US military official in Kabul familiar with McChrystal's review was quoted as saying.

Without significant rises, "we will lose the war," another US official involved in training Afghan forces told the Post.

The vision of McChrystal, who took command last month, would require the United States to spend billions more than the 7.5 billion dollars per year that it now has budgeted for Afghanistan and probably the dispatch of thousands more US personnel as trainers and advisers to the Afghan forces, the Post said

US President Barack Obama is deploying another 21,000 combat troops and trainers this year, bringing the total number of US forces in Afghanistan to 68,000 by the autumn.

The deployments are part of Obama's new strategy in Afghanistan, designed to intensify the fight against the resurgent Taliban by going after its strongholds. Since taking office, Obama has identified the conflict in Afghanistan as the largest national security threat facing the United States. (dpa)