KABUL - The NATO-led International Security Assistance Force (ISAF) formally ended its 13 years old combat mission in Afghanistan on Sunday.

In a ceremony held here to mark the end of 13-year old war on terror by the U.S.-led alliance and complete the handover of security charge to Afghan national security forces, the U.S. commander of NATO-led ISAF General U.S. General John F. Campbell said "Today marks an end of an era and the beginning of a new one. "

"We remember and honor those Coalition and Afghan heroes whom we've lost and the loved ones they left behind,"the general said. "Their sacrifices drive us to persevere. They drive us to finish this noble mission well, they drive us to win."

Ruling out the possibility of Taliban returning to power, the commander of U.S.-led NATO troops in Afghanistan pointed out"There is no turning back to the dark days of the past. We are not walking away. It's time for the enemy to heed President Ghani's call, lay down their arms, embrace peace and help rebuild the Afghan nation."

Speaking at the ceremony, Afghan presidential advisor on national security Mohammad Hanif Atmar appreciated the services of NATO-led troops in Afghanistan.

"We will never forget your sons and daughters who died on our soil. They are our sons and daughters as well," Atmar said.

"We are fully committed to working with you to meet our common security needs."

During the past 13 years of the U.S. and NATO-led ISAF war on terror, more than 3,500 servicemen with some 2,200 of them Americans have lost their lives in Afghanistan.

With ending the combat mission of the NATO-led forces, the security transition of the alliance to Afghan national security is completed and Afghan forces formally assume the security responsibility of their country from Jan. 1, 2015.

However, some 13,000 NATO servicemen, including 10,800 Americans, are supposed to remain in Afghanistan in 2015 to train and advise Afghan national security forces. (Xinhua)