Britain has ended combat operations in the Helmand province in Afghanistan, defense officials said Sunday.

They said U.K. troops have witnessed the lowering of the Union flag for the last time at the Camp Bastion complex in Helmand.

U.S. and Afghan soldiers also witnessed the ceremony, which marked the end of operations for the Southwest Regional Command, a U.S. and U.K. coalition operating under NATO's International Security Assistance Force, British officials said.

Camp Bastion has been the center of U.K. operations in Afghanistan since 2006. The handover of the base to Afghan control ends an important chapter in the 13-year Afghan campaign, which started after the terrorist attacks on the United States in 2001.

UK Defense Secretary Michael Fallon said the end of combat operations is being announced "with pride" and that Britain has helped give Afghanistan "the best possible chance of a stable future."

He said Britain's commitment to support Afghanistan will continue "through institutional development, the Afghan National Army Officer Academy, and development aid."

Brigadier Rob Thomson, senior U.K. officer in Helmand, said Afghan National Security Forces are "more than ready" to assume responsibility for security.

Britain suffered 453 fatalities during the campaign.