The US secretary of defence, Chuck Hagel, has said the gains achieved during the last 13 years in Afghanistan would be sustained.
Hagel, who arrived in Afghanistan on an unannounced trip on Sunday, also travelled to the eastern zone to meet Afghan and US forces on the Gambiri base.
Speaking to a hundred of US soldiers, Hagel said the idea was to "work our way, essentially, out of a job as we transition from the combat role we've had over the last 13 years" to a mission that puts the responsibility on Afghan forces.
He said Afghan security forces had made a lot of progress at the cost of much US blood and treasure since 2001. "We don't want to see that roll back downhill," Hagel remarked.
On Saturday, the secretary said Washington would keep as many as 1,000 more troops in Afghanistan than planned for the first part of 2015.
Earlier, US president Obama had announced to keep 9,800 troops in Afghanistan after the end of 2014.
Out them 1,800 will take part in training Afghan forces and the rest fight against possible terrorist threats.