Ashraf Ghani attributed the success in dislodging IS loyalists to ground operations, combined with close air support and the participation of retired commanders who had joined an elite commando division of the army to take on the extremists in districts of eastern Nangarhar province.
Over the past six months, IS fighters -- mostly disenchanted Taliban insurgents -- had dug in across Nangarhar. The Unites States largely provides air support in the anti-militant struggle in Afghanistan.
Initially, Afghan security forces let the two groups fight each other, as their assets were spread thin fighting insurgents elsewhere.
The valleys and mountains of the border region provide perfect cover for trafficking of mean, weapons, drugs, minerals and other contraband that provide millions of dollars in funding for the insurgency.
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Officials have said most militants claiming loyalty to IS are former Taliban fighters disillusioned with a lack of progress toward their goal of overthrowing the Kabul government. The Taliban's war is now in its 15th year.
With Afghan forces under pressure since the end of the US-NATO combat mission in 2014, concerns have risen that they are struggling against the insurgency alone.
The Taliban intensified and spread their fight last year, testing the resolve and capacity of the Afghan forces. With the training and backup of the pared-down US-NATO mission, the Afghan army and police, who also fight on the front lines, are slowly developing a defensive capability.