American soldiers patrol in Kherwar district of Afghanistan. ((Nikola Solic/Reuters))

The top military commander in Afghanistan is expected to tell U.S. President Barack Obama that up to 80,000 more troops should be deployed to the war-torn country.

The NATO commander in Afghanistan, U.S. Gen. Stanley McChrystal, is scheduled to meet with Obama on Wednesday.

McChrystal has already submitted a still-secret document to the president that reportedly includes a direct request for additional troops for the Afghan mission and provides recommendations on the number of forces needed.

Pentagon White House officials who have been briefed on the report told The Associated Press the three options contained in the document will be discussed at a high-level cabinet meeting and in a separate discussion between Obama and McChrystal on Wednesday.

NATO commander Gen. Stanley McChrystal leads a 103,000-member force in Afghanistan.

The officials, who spoke on the condition of anonymity because they weren't authorized to discuss the report's contents publicly, said one option calls for 80,000 more troops to be sent to the country.

An option of 10,000 to 15,000 troops and a compromise of 40,000 more forces are also contained in the report, the officials said.

Though each option still comes with high risk of failure for the Afghan mission, McChrystal argues in the report that fewer troops would bring a higher risk, the officials said.

British Prime Minister Gordon Brown announced on Wednesday the U.K. is prepared to increase its forces to about 9,500 contingent on allies carrying their fair share of the deployment.

Obama said Tuesday that he will decide in "the coming weeks" on a war strategy and the troops needed to carry it out. Though he said weighing military and security concerns are key parts of his decision, "another element is making sure we're doing a good job in building capacity on the civilian side."

Deadly mission

There are 67,000 American troops in Afghanistan, and 1,000 more are headed there by the end of December.

In the document McChrystal also concludes that corruption in Afghanistan could still allow terrorists to turn Afghanistan back into a haven.

Sending in additional troops would help secure Afghanistan but only in the short term, said Jay Parker, a Georgetown University foreign service professor and retired army colonel. Troops alone can't fix the corruption, the root of the problem, he said.

Now in its ninth year, the war in Afghanistan has been increasingly deadly for NATO forces and faces waning public support in the United States and allied nations.

Some of Obama's top advisers, chief among them Vice-President Joe Biden, favour significantly increasing the use of unmanned Predator drones and special forces for the kind of surgical anti-terrorist strikes that have been successful in Pakistan, Somalia and elsewhere.