A senior military official said Allen offered Defence Secretary Leon Panetta three plans, each with different troop levels - 6,000, 10,000 and 20,000 - and risk-factor probabilities, The New York Times reported.
The 6,000-troop option would probably pose the highest risk of failure for the US effort in Afghanistan, the option with 10,000 troops would carry a medium risk and the 20,000-force option would be the lowest risk of the three, the official said.
However, the official told the Times the more important consideration in the success of any post-2014 US mission in the Asian country depended on how well, or whether, the Afghan government could deliver basic services to its citizens.
Defence officials told the Times it wasn’t clear if President Obama had studied the options, but said they expect him to discuss them with Afghan President Hamid Karzai next week in Washington.
The Obama administration recently has been considering the size and mission of a US force that would remain after 2014 to help boost Afghan stability. Currently, about 66,000 US troops are in Afghanistan.
Under an agreement between Nato and the Afghan government, the Nato combat mission ends Dec. 31, 2014, when the Afghan Army and police assume full responsibility for their country’s security.