US President Barack Obama is probably weighing three options for his new Afghanistan strategy, analysts at the New York Times said.

While each option proposes different level of troop increase, what really matters is how to fight the war under these options, they said in an analysis published by the newspaper on Monday.

US Defense Secretary Robert Gates, Secretary of State Hillary Rodham Clinton and Chairman of the Joint Chiefs of Staff Mike Mullen have coalesced around a plan to send 30,000 or more troops to Afghanistan, which is called the middle option.

US Vice President Joe Biden advocates a plan calling for sending the lowest level of additional troops -- 10,000 to 15,000. That is the low option.

The high option calls for 40,000 additional troops, which was outlined by Stanley McChrystal, the top US and NATO commander in Afghanistan.

Obama probably will announce the new strategy in the first week of December and he is expected to meet his war council this afternoon.

Should he decide to send 40,000 additional troops, the military would have enormous flexibility to deploy as many as 15,000 forces to the Taliban center of gravity in the south, 5,000 to the critical eastern border with Pakistan and 10,000 as trainers for the Afghan security forces, analysts said.

The rest could be deployed across the country, including to the NATO headquarters in Kabul, the capital, and in clandestine operations.

If the president limited any additional American troops to 10,000 to 15,000, the military would deploy them largely as trainers, with some reinforcements likely in the southern province of Kandahar, the Taliban's "spiritual home".

It would focus on eliminating al-Qaida leadership in Pakistan through drone attacks.

Under the middle option, there might be 5,000 trainers rather than 10,000, and fewer troops to spread across the country, although there would still be a concentration in the south.