US Defense Secretary Jim Mattis arrived in Afghanistan Monday. 
During the visit, Mattis will meet Afghanistan's President Ashraf Ghani, government officials and US troops. 
He will also visit the headquarters of Operation Resolute Support, the NATO-led mission to train and advise Afghan security forces. 
The US Defense Secretary was due to meet with his Afghan counterpart, but hours before Mattis touched down in Kabul, Ghani announced that his Defense minister and Army Chief of Staff had resigned with immediate effect. 
The US Defense Department said that the Secretary tour is aimed at reaffirming key US military alliances, engaging with strategic partners and discussing cooperation to counter terrorism.

Source: QNA