The Afghan president, Ashraf Ghani, has pledged to recapture the northern city of Kunduz from the Taliban as government troops launch a counter-offensive to drive out the militants.

"Afghan security force made achievements today in Kunduz Province. They have recaptured some parts of the government buildings. New reinforcements have reached Kunduz and Baghlan and a battalion from the national army will get to Kunduz soon," Ghani said in a televised address on Tuesday.

He noted that the Taliban militants have "suffered heavy causalities in some air strikes and ground fighting."

"I want to assure all of my countrymen that Kunduz is under our management. Therefore we should not be worried about enemy plans of stirring fear in the area," Ghani said

The comments come a day after the Taliban militants overran the city. Afghan officials confirmed that the Taliban had stormed government buildings and taken over a state-run hospital.

Local residents said Taliban militants were setting up checkpoints and sealing off exit routes.

"From this morning, the Taliban have been setting up checkpoints in and around the city, looking for the government employees," The Associated Press quoted one resident as saying, adding, "Yesterday (Monday) it was possible for people to get out of the city, but today it is too late because all roads are under the Taliban control." 

Wahidullah Mayar, the spokesman for the Public Health Ministry, said Kunduz hospitals received "172 wounded patients and 16 dead bodies so far."

Kunduz Province is strategic as it is located on a crossroad that connects key regions of the country. The city has been witnessing battles between security forces and militants since April.

The stunning fall of the provincial capital dealt a major blow to Afghanistan's US and NATO-trained security forces.

Afghanistan continues to face insecurity 14 years after the US and its allies invaded the country as part of Washington’s so-called war on terror. Although the Taliban were removed from power as a result of the invasion, many areas in the country are still threatened by insecurity.