The pledge was made by US officials during a meeting with Afghan delegation led by President Mohammad Ashraf Ghani to the United States.
President Mohammad Ashraf Ghani has asked Washington to continue its assistance and funding Afghan forces and also leaving its forces for a longer period in Afghanistan than initially planned.
United States has around 10, 000 troops in Afghanistan but plans to reduce its number to as less as 1, 000 around 2017.
Though, President Ghani is seeking a larger number of US troops in the country amid fresh concerns that ISIS is eyeing on getting a foothold in Afghanistan.
President Ghani has told NBC News that ISIS is mulling Afghanistan strategic for its broader war and creating a caliphate in the Middle East.
Reports indicate that some previous members of Taliban group are regrouping under the flag of DAESH or ISIS in Afghanistan.
So far two Taliban commanders who were recruiting and fighting for DAESH in Afghanistan have been killed.
Mullah Abdul Rawouf and Hafiz Wahidi were the two ISIS commander recently killed in southern Afghanistan.