U.S. Secretary of Defense Jim Mattis is in Afghanistan assessing the possibility of sending more troops to the war-torn country.
General John Nicholson, the top US commander in Kabul, recently told Congress that he needed a few thousand more troops to keep Afghan security forces on track to eventually handling the Taliban insurgency on their own.
That attack on the compound of the 209 Corps of the Afghan National Army in northern Balkh province unfolded when gunmen and suicide bombers disguised in army uniforms hit the compound.
The US has thousands of military forces in Afghanistan.
The resignations, announced in a terse one-line statement from the presidential palace, came amid fury over the Taliban assault on an army base outside the northern city of Mazar-i-Sharif on Friday.
Mattis said Monday that he is still deciding whether he'll ask President Trump to send more troops.
There are now about 8,400 US troops and another 5,000 North Atlantic Treaty Organisation forces in the country, and Nicholson and other USA military officials have said that several thousand more are needed to continue training and supporting Afghan forces. The Taliban has pledged that the attack is just the beginning of its annual spring offensive.
Soldier tells Anzac crowds of losing legs
Medowie RSL sub-Branch Honorary Secretary, Neil Biggar, told News Of The Area, "As Australians, we owe so much to those people". We now stand shoulder-to-shoulder with Turkey, remembering our fallen men and the spirit in which they fought.
There was no immediate word on casualties in the attack on Camp Chapman, one of the first US bases in Afghanistan and one that has had a significant Central Intelligence Agency and Special Operations presence.
Mattis's visit - taking place a little more than a week after National Security Adviser H.R. McMaster's trip - comes at a precarious time in the more-than-15-year-long war.
US State Department spokesman Mark Toner said the Afghan defence minister and his army chief resigned in the wake of the attack. Another official said the death toll of the soldiers was likely to go even higher. The defence ministry said the attackers were all killed.
Mattis said he expects an ongoing dialogue with the Afghan leadership in order to provide his best assessment and advice to US President Donald Trump.
At least 150 were killed when suspected Taliban insurgents penetrated a US-operated military base in the eastern province of Khost last Friday, opening fire on mostly unarmed soldiers, who were eating a meal, and leaving a mosque after Friday prayers.
And last month, Gen. Joseph Votel, commander of U.S. Central Command, told the House Armed Services Committee it is "fair to assume" that Russian Federation is proving arms to the Taliban.
Washington claims that the massive military presence is only aimed at maintaining security across the country until Afghan military forces are ready to take over the responsibility.