The German chancellor, Angela Merkel, has pledged to give $193m a year to help support Afghanistan's security forces after NATO forces withdraw from the country in 2014.

Merkel and Hamid Karzai, Afghanistan's president, hailed a "milestone" in relations on Wednesday in Berlin after signing a a partnership agreement that ensured support for Afghanistan's police and military following the expected pullout of the foreign coalition.

The pledge came a day after Australia, which also has troops in the international alliance in Afghanistan, pledged to provide Afghan security forces with $300m over a three-year period after the withdrawal.

The funding by countries involved in NATO's war against Taliban and al-Qaeda fighters aims to secure Afghanistan's future amid fears that unrest and turmoil will spread further after the foreign forces hand over full responsibility to the country's security forces.