Afghan President Ashraf Ghani on Thursday announced his nominee for the country's defence minister post in a bid to complete his cabinet after months of infighting as the Taliban's annual spring offensive grinds on.

Ghani nominated Mohammad Masoom Stanekzai, the secretary of the High Peace Council for the crucial position left vacant for months over disagreements between Ghani and his chief executive officer, Abdullah Abdullah.

"Mr. Masoom Stanekzai will be our next minister of defence," Ghani told a gathering of foreign delegates in Kabul. He added he was working hard to appoint other senior officials including provincial governors.

Stanekzai, who previously served as an adviser to ex-president Hamid Karzai, will need to be approved by the parliament.

Excluding the latest announcement, Ghani has so far appointed 24 of the cabinet's 25 ministers, a process that has been fraught with delays since his inauguration last September.

Public criticism over the failure to appoint a defence minister -- reportedly due to differences between Ghani and Abdullah over their choice of candidate -- has been especially fierce, with many linking the leadership vacuum with a recent uptick in deadly insurgent attacks.

The delay has stoked fears of instability in the troubled nation as NATO troops pulled back from the frontlines after 13 years of conflict against the Taliban.

On Tuesday, a Taliban car bomber ripped through the parking lot of the justice ministry in Kabul killing four people and wounding dozens of others in the latest in a string of attacks to shake the Afghan capital.

The militants launched their spring offensive late last month marking the first fighting season in which Afghan forces are battling the insurgents without the full support of US-led foreign combat troops.

NATO's combat mission formally ended in December but a small follow-up foreign force has stayed on to train and support local security personnel.