WASHINGTON: The United States on Tuesday ordered non-essential staff to leave its Kabul embassy, citing increased threats as Washington prepares to end its 20-year war.

The State Department in a travel advisory said it had "ordered the departure from US embassy Kabul of US government employees whose functions can be performed elsewhere."

Ross Wilson, the acting US ambassador in Kabul, said that the State Department took the decision "in light of increasing violence and threat reports in Kabul."

He said that the order affected an unspecified "relatively small number" of employees and that the embassy would remain operating.

"Personnel who are urgently needed to address issues related to the drawdown of US forces and the vital work we are doing in support of the Afghan people will be able to remain in place," Wilson wrote on Twitter.