"I am grateful to President Trump and the American people for this affirmation of support [...] for our joint struggle to rid the region from the threat of terrorism," Ghani declared in a statement.
He said the new strategy would increase the capacity of the training mission for Afghan national security forces, including enhancing its fledgling air force and doubling the size of the Afghan special forces.
The US president didn't give a timeline or specifics about the expected troop surge, although it's believed it will involve about 4,000 extra troops.
"I will not say when we are going to attack, but attack we will," Mr Trump said.
Australia's Defence Minister Marise Payne insists that from the United States and that Australia will not be changing its role in Afghanistan.