U.S. Secretary of Defense Jim Mattis is in Afghanistan assessing the possibility of sending more troops to the war-torn country.
His arrival Monday in Kabul comes on the heels of a weekend attack on a northern Afghan army base by the Taliban.
At least 130 Afghans were killed and the country's army chief and defense minister resigned.
That attack was the biggest ever by the Taliban on a military base in Afghanistan. It involved multiple gunmen and suicide bombers in Afghan army uniforms who penetrated the compound in northern Balkh province.
Two top American military leaders are advising the Trump administration to send a few thousand more troops.
The Taliban has redoubled its efforts as the U.S. scaled back involvement in Afghanistan in recent years.
The attack in Balkh raises serious questions about the Afghan military's ability to stand on its own in the battle against the insurgency following the withdrawal of foreign combat forces at the end of 2014.
The American and other foreign troops remaining in Afghanistan are now mostly acting in an advisory and training role, with some combat assistance.