Earlier reports claimed NATO was considering a postwar force of between 8,000 to 12,000 troops, tasked with training and advising Afghan National Security Force (ANSF) units. Those ANSF units will take over security operations in the country once U.S. and allied forces leave next year.
However, Pentagon officials quickly shot down those proposed troop numbers, claiming negotiations were still ongoing between Washington, Kabul and Brussels.
Gen. John Allen, former head of all U.S. forces in Afghanistan, suggested as little as 6,000 U.S. soldiers or as many a 10,000 could remain in country after 2014. Administration officials have also floated the notion of leaving no American soldiers behind after the withdrawal deadline.
Marine Corps Gen. Joseph Dunford, Allen's replacement, will be the top U.S. officer to oversee the final American withdrawal and eventual post-2014 force in Afghanistan.
But Rasmussen on Monday dismissed the so called "zero option" floated earlier this year by the White House.
"President Karzai assured me today that Afghanistan wants a NATO-led training mission to stay, to train, to give advice, to assist the Afghan security forces after 2014," Rasmussen said.
While the actual force numbers are still in flux, Rasmussen was was able to provide Karzai and other top Afghan defense officials details on the NATO postwar mission, dubbed Operation "Resolute Support."
"It takes some time to stand up a new training mission," he said regarding the NATO postwar mission. "Of course, and we will need the clarification [from Kabul] within the next few months" before the operation can begin in earnest.
DOD and the White House are also crafting a postwar plan for Afghanistan, however that work continues to be stymied by the lack of a troop immunity agreement with Afghanistan.
Negotiations between American and Afghan leaders on the new troop immunity deal are scheduled for later this year, Karzai said in January.
If finalized, U.S. forces left behind in Afghanistan would not be subject to criminal prosecution by Afghan courts for counterterrorism or other combat operations conducted in the country after 2014.
The United States has similar agreements in place with each country where American forces are stationed. The lack of such an agreement prevented Washington from having a postwar force in place in Iraq when U.S. troops withdrew from the country in December 2011.
The lack of a troop immunity deal for Iraq ultimately the stage for the ongoing wave of sectarian violence against Iraqi forces and civilians in the country.
During last February's State of the Union address, President Obama announced the administration would be pulling out half of the 66,000 American service personnel in Afghanistan by this spring.
The final 32,000 American forces remaining in Afghanistan after this spring's planned troop withdrawal will start coming home following the country's presidential election in April, 2014 — officially ending America's combat role there, former Defense Secretary Leon Panetta said that same month.