The special United States peace envoy to Afghanistan Zalmay Khalilzad has stepped down.

In a tweet, he said I am of course saddened on behalf of the Afghan people that, despite our best efforts and extensive shuttle diplomacy we failed to end 40-year conflict in a constructive spirit and with a fair compromise.

Meanwhile, US Secretary of State Antony Blinken in a tweet said thank you to Ambassador Zalmay Khalilzad for decades of tireless service to the United States.