On January 1, the US-led International Security Assistance Force (ISAF) combat mission will be replaced by a NATO "training and support" mission.

The closing of NATO's combat mission comes at the end of the country's deadliest year during the war, which saw at least 4,600 Afghan soldiers and police killed and many other civilian deaths.

A NATO official said US General John Campbell, the ISAF commander, would lead Sunday's ceremony at the force's headquarters in Kabul.

The United Nations says that civilian casualties hit a record high in 2014, jumping by 19 percent with 3,188 civilians killed by the end of November.

Afghan's police and army have also suffered a grim death toll, with fatalities soaring to more than 4,600 in the first 10 months of 2014 -- far higher than all ISAF deaths since 2001.